Public Planting Establishment (Pests & Diseases of Public Spaces)
The purpose of this project is to investigate, describe, and define plant pests, diseases and
disorders, vandalism in context with open public spaces and the historic and contemporary
methods of identification, prevention, mitigation and control.
Without a thorough understanding of the susceptibility of planting schemes to pest,
disease, disorders and vandalism and how to manage/prevent them, poor design will be
inevitable. Planners, developers, local authorities, etc, are looking towards environmental
(sustainable) design for efficient, cost effective schemes. Environmental design is “the
philosophy of designing physical objects, the built environment and services to comply with
the principles of the economic, social and ecological sustainability” (McLennan, 2004).
This report will look to answer many questions, among them:
• What are plant pests/diseases/disorders?
• What is vandalism?
• What are their effects on public spaces?
• What are their causes?
• How are they identified?
• What are their past/present/future controls & how are they prevented?
The method to answering these questions will be through studying and analyzing a
part of the existing material on the subject, in regards to landscape architecture. The report
will then contextualize this information and form conclusions and recommendations based on
This report will be relevant and useful in terms of landscape architecture and the
preparation of a planting scheme resistant to pests, diseases, disorders and vandalism after a
2. Causes & Effects
2.1 Plant Pests
Plant pests are animals that cause damage to cultivated, ornamental and vegetable, plants
(Bell, 2002). They are most active and damaging in mono-cultural environments. Most
pests, as in the case of invertebrates, are seasonal and their life cycle is closely related to, and
utterly dependent on plants. The largest group in the category of plant pests is Insects
(Invertebrates). Damage caused by plants pest includes; sap sucking, disease transmission,
defoliation, leaf, stem and root mining/tunnelling. A plants immune system may react badly
to attack from a pest leading to the formation of blisters. Infection from diseases is also made
easier by initial attacks of pests (Brickell, 2002).
It is important to control plant pests as many are vectors for viruses and diseases,
carrying them from plant to plant. Others meanwhile, cause tissue damage to planting,
allowing diseases to enter the plant(s) through the wound (Secondary Infection). Plant pests
can be divided into the following groups: Arthropods, Molluscs, Nematodes & Vertebrates.
2.1.1 Animal Pests
Animal pests include Deer, Dogs, Cats, Birds & Squirrels to name but a few. They
are larger than invertebrate pests and so can cause much damage on their own. The
biggest complaint of animal pests is bark damage. This is the source of much
tree/plant damage, due to secondary infection from disease (Bell, 2002).
Damage done to plants is usually superficial, with new buds & shoots eaten
and shrubs dug up or trampled upon. Animal pests are controlled and prevented by
repellent sprays, fences and mechanical scarers. In the case of rats and mice, poisons
are used in conjunction with traps.
The path to avoiding problems with animal pests is to design areas unattractive
to them. This is done by removing possible sites for nesting and shelter and using
plants which do not appeal to their taste buds. Fencing can also be used to prevent
access or to shield plants from damage. Decoy plants can also be used to divert
attention away from plants susceptible to damage (Brickell, 2002).
2.1.2 Invertebrate Pests
There is nearly 20 million species of insects on this planet. An estimated 50% of this
plant material feed on living plants. Some species attack a wide range of plant species
and others need a specific plant to thrive (Bell, 2002). The result is massive losses
and costs in terms of maintenance & repair of public planting spaces. These facts
stress the importance of an integrated pest management system, through chemical,
biological or other means.
Plants are important to invertebrate pests in terms of food, shelter and
reproduction. Invertebrates are problematic, not only in terms of the damage they do,
but also the viruses and other diseases that they are vectors for (Brickell, 2002).
Through understanding of invertebrate pests, they can be destroyed upon discovery or
repelled completely by selective planting.
By designing planting schemes effectively, the landscape architect should be
able to interrupt the life cycle of invertebrates, increase the number of their natural
predators and overall produce a planting scheme that is resistant to invertebrate pest
damage (Bird, 2004).
Woolly Aphid (Fig. 1)
2.2 Plant Diseases & Disorders
Plant Diseases are caused by viruses, bacteria and fungi. Many are classified as Secondary
infections. This means that they infected the plant due to the action of another living
organism, i.e. entry through a bark wound caused by Deer (Bell, 2002). They spread easily
with the aid of wind & mechanical vectors. The amount of damage done to a plant by a
disease is dependent upon a number of factors, such as weather, growing conditions, pre-
existing health of plant & other present aliments (Brickell, 2002).
By understanding how diseases, and disorders are caused, the landscape architect will
be able to prevent and/or mitigate their effects. Disease spread by wind can be
stopped/hindered by a barrier of disease resistant trees, sheltering a susceptible area of
planting. Poly-cultures (i.e. mixed plantings) can also be used to produce disease/disorder
resistant planting schemes (Bird, 2004). The right design, with the right choice of plants can
help offset the effects of pollution on planting, i.e. using Ferns to absorb heavy metals out of
soil and away from other plants.
A fungus is a plant without Chlorophyll. It obtains nourishment as a parasite through
symbiosis. It spreads and grows through mycelium and spores. All infected leaves,
even those that fall, should be destroyed to curb the spread of the disease (Bell, 2002).
In comparison, fungi diseases are much more common than bacterial infections.
Along with several strains of bacteria and viruses, some species of fungi have become
resistant to chemical sprays and treatments (Brickell, 2002).
Bacteria are single celled organisms. They survive as either saprophytes or parasites.
They spread by contaminated soil and tools. They can also be moved by wind, rain,
insects and survive on the surface of seed coats, attacking when germination occurs.
They infect plants through the stomata or open wounds. This is why it is
important to seal all wounds, even after pruning, with Aqua-seal 50 to act as a semi-
permeable barrier that stops infection. Bacteria cause abnormal cell growth and
eventually cell/plant death. Some bacteria are used in a beneficial way, in terms of
biological controls (Bell, 2002).
Bacterial Canker (Fig. 2)
Viruses are sub-microscopic particles which clone themselves to represent their host
cell. All viruses are parasites and have no other means of surviving (Bell, 2002).
Viruses move from plant to plant by mechanical or vector means. Viruses spread
through the host plant means of systemic infection from one plant cell to the other.
When the virus enters the phloem cells of the plant, it multiplies rapidly. Plant death
doesn’t always, but most certainly, follows this stage.
2.2.4 Physiological Disorders
Plant (physiological) disorders are caused by non-infectious agents. They produce
disease like symptoms in the affected plant. They have many causes including
nutrient deficiency, pollution, water stress and light (Brickell, 2002). Unsatisfactory
growing conditions and fluctuating temperatures/water and food supply are the
commonest causes. Physiological disorders make plants more susceptible to pest or
disease attack (Secondary Infection). It is only in extreme cases that a plant will die
solely from a physiological disorder.
Nutrient deficiency occurs when the nutrient supply to the plant is inadequate
(Tracey, 2007). Nutrients may be still present in the soil, but unavailable to the plant
due to extremes in pH, water stress and/or high cation exchange capacity, caused by a
high clay content in the soil.
Nitrogen Deficiency (Fig. 3)
Pollution causes physiological disorders in plants by affecting photosynthesis
(pore/leaf blockage) and introducing poisonous substances into the plant supply.
Water stress causes disorders in plants by excess/inadequate transpiration and an
unstable water supply. Light, can become a cause of disorders in plants (i.e. lack of
light leading to etiolation) (Bell, 2002).
Vandalism has been used as a broad term to describe anti-social behaviour, accidental or not,
to criminal activity. Furthermore, vandalism can be divided into 4 sub groups:
• Inexplicable vandalism
• Deliberate vandalism
• Incidental vandalism, &
• Institutionalized vandalism
The term inexplicable vandalism covers rare, destructive occurrences of vandalism.
Its causes are numerous, from chance happenings to psychotic behaviour in individuals. It
cannot be anticipated, but protection can be provided to potential fragile targets. Mitigation
of this form of vandalism is available through judicial proceedings & law enforcement
Deliberate vandalism is the damage, destruction or theft of facilities and properties of
a specific site/location. The second most common form of vandalism, overall, it causes more
damage to facilities & cost more to prevent and repair. Motivation for damage by this type of
vandalism is numerous (Christiansen, 1984). It can be used as a medium for financial gain,
i.e. Removal of fencing for scrap, stealing and re-selling of expensive hardscape materials.
Damage to facilities can also be caused to gain access and use. Deliberate vandalism also
covers the area of “graffiti writing” or “street art”. This is done with no malicious intent in
mind, but to simply convey a message. However, it is costly to remove and may offend.
Incidental vandalism has the highest occurrence over all other forms of vandalism.
Fortunately, it is not the most damaging. It is easily preventable and damage caused can be
repaired without high costs. Incidental vandalism covers wear and tear of materials over
time, littering, damage to plants (picking flowers, shortcuts, carving names into bark, etc) and
general disregard for property. Incidental vandalisms cause(s) lies in the social fabric of the
local community (Goldstein, 1996).
Institutionalized vandalism is “accepted” or expected damage to public spaces. It
occurs with public celebrations, events and gatherings in public spaces. With large
concentrations of people in public spaces, damage is expected and the accepted course is to
simply repair the damage. The only control for this form of vandalism, short of closing the
public space, is to demand deposits from those who book or use the space. This leaves
responsibility with them (Goldstein, 1996). If damage costs exceed the received deposit,
fines can be issued, with a ban from the said public space, until the fine is paid in full.
All the previously discussed forms of vandalism have their roots of destruction based
in their social environment; however, the extent of damage done is directly influenced by the
surrounding physical environment. While improvements in social mentality can be made,
they will not alone stop vandalism in public spaces. The same can be said for physical
barriers. These can encourage or “incite” vandalism and can even become vandalized
themselves (Christiansen, 1984).
The causes of vandalism have their roots in the physical and social environment, both
perceived and actual. In this section the causes of vandalism will be looked at under
the following headings:
• The Social Environment
• The Physical Environment
• Sense of Ownership (Lack of) & Community Interaction
There is rarely one cause of vandalism. The factors above work together, to create an
undesirable environment that results in vandalism of public open spaces.
The social environment is influenced by the physical environment and vice
versa. The presence of anti social behaviour is not the fault of the designer, but
creating an environment that doesn’t control it and/or exacerbates the problem is. It is
important for a designer to understand the social environment relevant to the
surrounding area (Tracey, 2007). Only then can the designer create an effective
design that gives the local community a sense of ownership and pride. It also
indicates what degree of protection from vandalism is needed.
Bad design of a physical environment can make a bad problem worse.
Without proper design considerations, unintentional features that exacerbate
vandalism will be created. These are called “Crime Features”. They include areas
with insufficient lighting, pathways out of sight and areas with low usage/pedestrian
traffic. Elements of this bad design can be both real and perceived. People’s
perceptions will lead to an area out of sight, with low traffic and low light to being
dangerous. Perceived areas of danger will lead to those said areas becoming
abandoned and eventually, havens of anti-social behaviour and vandalism. Also poor
understanding of design will increase the likely hood of vandalism (Christiansen,
1984). For example, the concept of permeability, which increases pedestrian flow,
traffic & access through the use of pathways, intended for positive interactions. This
can provide escape pathways for vandals, increasing the problem.
Positive community interactions with public open spaces lead to high
pedestrian concentrations in small areas and increase public space usage. The sense
of getting caught will deter most vandals. Attracting high level of pedestrians to the
area can be done by sufficient lighting, fencing, minimal areas hidden from sight etc.
However, high levels of pedestrian flow/usage will allow coverage & anonymity of
criminals. Involving the community in the public space through the use of design
(inclusion of community gardens, etc) will bring greater security to the area. Since
vandalism itself is (usually) rooted in the local community, by involving patrons of
the public space it brings a sense of ownership (Goldstein, 1996).
Pest and disease control methods have been practiced over many centuries. Many were
formulated from trial and error. While ineffective on their own, they are usually integrated
individually into a larger system of controls mutually supporting each other. Controls can be
defined as measures taken to remove or reduce damage/loss below a level of economic value.
The following sections will describe various controls and their methods.
3.1 Integrated Pest and Disease Control
Integrated control is the best practice in the limitation and management of pest & disease
problems. It focuses on prevention, cure and control. Integrated control uses several systems
to be effective (Bell, 2002). These can include companion planting, xeriscaping, biological
control and permaculture.
Integrated control is focused more on prevention, rather than cure. This proves more
successful in the long run to plant health and in keeping maintenance costs down. This is
done by the selection of strong, resistant, vigorous growing plants (Brickell, 2002).
For the landscape architect to implement an integrated control effectively, they must
understand the needs and properties of their planting selection(s). This is where the best
management practice of integrated control comes into action. This involves:
• Analyzing the site properly and identifying plants that would thrive in this
• Identifying pests and diseases that would be problematic in this environment
• Identifying plant species/cultivars that would be resistant to these pests &
• Using design to create optimum growing conditions for selected plants so they
have a competitive advantage over pests and disease
• Using design to minimize the chances of a physiological disorder occurring
within the planting system(s)
• Inspection of selected plants:
o Before purchase
o On delivery to site
o After planting on site
o At regular intervals after planting on site
3.2 Chemical Controls
Insecticides are used to control and eliminate local invertebrate populations. They
come in a variety of powders, dust and liquid applications. They are now mostly
applied by pressure sprayers. There are 3 types of Insecticides:
1) Insect Contact
Mostly used on Aphids and other insects with high populations in close quarters.
They are only effective in local populations. The Insecticide will only kill whatever it
comes into contact with. It has no residual effect after application.
2) Leaf Contact
Leaf contact Insecticides work by coating the leaves of plants. When insect pests,
such as caterpillars/aphids eat the treated leaves, they die. They also have an after
effect. However, the treatment can be washed off the leaves by rainfall.
The Insecticide is absorbed into the plant and its sap. Systemic insecticides are
effective and do not have to come into direct contact with pests. They also have an
after effect, which is not washed off by the rain. Complete plant cover is not essential
and one application provides enough protection for the growing season.
Chemical insecticides are not popular due to their association with pollution,
environmental damage and cancer. Also, species of invertebrates pests are becoming
immune to the most widely used sprays, making them more problematic and resistant
(Brickell, 2002). Furthermore, other beneficial invertebrates are becoming caught in
the crossfire and having their numbers reduced (Bird, 2004). Many active ingredients
have been banned, leading to no soil pest insecticides and a narrower range of
systemic insecticides. Another danger associated with Insecticides is Accumulative
Toxicity, i.e. DDT (Bell, 2002).
Less widely used than insecticides, Fungicides are used to prevent, control and cure
diseases caused by fungi (Brickell, 2002). There are two types:
Preventive fungicides work by coating the leaves and destroying any spores which
land on them. To be truly effective, the fungicide must be applied before the first
symptoms of the disease.
Systemic fungicides work by moving inside the plant, into its sap. As a preventive, it
is much more successful than the preventive fungicide as it gets greater coverage.
As with insecticides, the range of chemical fungicides has been narrowed due
to environmental damage caused by their extensive use. Organic fertilisers are proven
and tested. These include sulphur & copper applications (Bell, 2002).
Phytotoxicity occurs in plants liable to severe reactions to insecticidal and fungicidal
sprays/powders. Plants most susceptible to phytotoxicity are those with a pre-existing
physiological disorder (stress), in flower, young immature plants and others who are
sensitive at certain periods during their growing cycle. Also, several plants may
become damaged if a group of different plants are being sprayed with the same
chemical, with others being more prone to an adverse reaction (Brickell, 2002).
Good design can avoid these problems. If chemical (insecticides, fungicides,
etc) are to be used in a planting scheme, proper management to avoid complication
must be implemented. Monocultures can be effective, as there is no risk of a reaction
to the chemical from other plants. Or, design can be used to remove the risk of
phytotoxicity altogether, by making the use of chemical control redundant. Several
methods to do this will be discussed in the following sections.
3.3 Organic Controls
3.3.1 Companion Planting
Companion planting is a gardening/landscaping technique that carefully chooses and
grows compatible plants with one another for their mutual benefit. It origins lay in
European cottage gardens from the Middle Ages (Bird, 2004).
Companion planting is quite a desirable practice as a mixture of species of plants
that have different tolerances to disease, bacteria and pests will lessen damage done to
a planting scheme (Lamb, 2008). This approach to planting also advocates the use of
“green manures”, plants that draw nutrients from deeper soil and make them available
to other plants when they are tilled back into the soil. This solves any troublesome
encounters with nitrogen deficiencies. This practice is also repeated with leguminous
plants that fix nitrogen from the air (Tracey, 2007).
Companion planting is also planned to cover ground throughout the year. This
stops or impedes the colonization of algae, moss and the invasion of weeds. The
arrangement of planting is paramount to the success of companion planting. Different
plant groups are planted together to repel pests, resist disease and prevent nutrient
deficiencies in the soil. This practice focuses on mixed cultures rather than
monocultures (Brickell, 2002).
Monocultures tend to be more prone to disease and pest damage.
Concentrations of mono-cultural planting allows for the rapid spread and reproduction
of pests and diseases (Lamb, 2008). In most cases, chemical controls must be used to
ensure the success of a monoculture. In terms of pests, mixed cultures control their
numbers by attracting the problem pest’s natural predators into the vicinity (Bird,
2004). For example, an area dedicated simply to roses would be a haven for greenfly,
with the problem likely to spiral out of control as roses do not attract ladybugs or
lacewings, aphid’s natural predator (control). Also planting can be used to repel pest
away from the planting scheme by using plants such as Marigolds, Lavenders and
Basil. Other plants can be used to attract pest away from other plants (Decoy Plants),
i.e. Sunflower. Disease resistance is another cornerstone of companion planting.
Champions of companion planting tend to favour older stocks of plants as modern
plant breeding has eliminated certain genes and immunities from new plant cultivars.
3.3.2 Biological Control
Biological control is the direct or indirect use of living organisms to reduce the
number of damaging pests below a level of economic importance (Brickell, 2002).
Biological control describes the process of limiting damage done by pests with the
purposeful introduction of natural predators, parasites and diseases harmful to them.
Biological control is a naturally occurring force that is replicated and implemented to
remove the need for chemical insecticides (Bell, 2002). It is mostly used to deter and
control pests through predatory means. However, biological control practices are also
set up to stop fungi and disease becoming a problem.
Biological control is an attractive option to pest management. It has few
negative factors associated with it, unlike chemical controls and unlike chemical
controls, once established it has no additional costs and is relatively permanent (Bird,
2004). In terms of predatory pest control, predators will either hunt and consume
their prey or develop a parasitic relationship with the pest. Biological control is
designed to use living organism that have no negative effects on non-target/beneficial
However, it is establishment of Biological controls that is the problem that has
plagued growers & researchers. It is a simple fact that predators are driven by instinct
and, once unleashed, may eat beneficial insects instead of pests. Transport of
biological controls is another problem, as many predatory species die from being
incorrectly handled and underfeeding. Another drawback to implementing such a
programme is timing. Many pests do most of their damage to young plants in early
spring, when very few predators are active (Bell, 2002). Living organisms used in
biological control require many optimum conditions to be present for the practice to
be successful, such as temperature, humidity, pest numbers and time of year/stage of
Xeriscaping is a landscaping philosophy that uses as many native, drought resistant
plants as possible and arranges them in an efficient design that conserves water
(Fuller, 2008). It was first developed by the Denver city authority to combat the
deadly droughts that faced the city during the 1970’s. Xeriscaping can reduce
irrigation use by 60%. Native planting is used because it is adjusted to the climate.
Drought tolerant planting is used on the outskirts of the design, or the furthest points
from the water source.
Xeriscaping is effective at managing diseases and fungi. This is because it
uses a lot less water, which is vital for the colonization, reproduction and spread of
diseases and fungi. Without adequate moisture, diseases cannot capitalise. With
plants covering the ground and appropriate mulch, no weeds (which may be
susceptible to diseases) can colonise.
The important part with xeriscaping is to ensure free draining soil and to avoid
any areas of pooling water. Appropriate mulches can also be used, ideally inorganic,
as organic mulches (bark) can rot, if wet for prolonged periods, giving diseases an
environment to thrive in. However care must be taken with inorganic mulches as they
absorb heat from the sun, increasing transpiration from plants and soil (Fuller, 2008).
Xeriscaping controls Disease by removing one of its necessary needs, water.
However, in a climate such as Irelands, Xeriscaping would most likely fail as a
Peramculture, otherwise known as “Permanent Culture” or Permanent Agriculture”, is
the intentional design & maintenance of agriculturally productive ecosystems that
have the diversity, stability & sustainability of natural ecosystems, according to
permaculture.org. Permaculture is based on philosophies of working with nature,
instead of against it.
Peramculture incorporates biological controls, mimicking natural relationships,
companion planting and nutrient recycling (Lamb, 2008). It is also known as
“Restoration Ecology”. The following are the principles of permacultural design:
1. Zones: Areas requiring high maintenance/traffic are placed closer to the
centre/access pathways. This minimizes energy and time wasted by
2. Sectors: This principle works in conjunction with the zoning principle. It is
a method of further dividing areas of priority within zones.
3. Relative Location: This involves the placement of activities/amenities
beside complementary areas within the same zone or adjacent sectors. This
maximises energy output from a single area.
4. Single Elements With Multiple Functions: Structures, plants and other
elements are placed and designed to meet and supply multiple needs. This
maximises their energy output for the amount of space they take up.
5. Single Functions With Multiple Elements: This principle involves the use of
multiple elements to replace a single element if it fails. It is often used as a
6. Energy Efficiency: This principle dictates that sites must have as little
external energy input as possible. This means sites shouldn’t need additional
fertilisers, chemical sprays, heavy maintenance etc.
7. Biological Resources: This involves the use of natural relationships to
control weeds, pests and disease. Examples include biological control,
companion planting and xeriscaping.
8. Plant Succession: Planting schemes develop and evolve over time. By
designing an area effectively, plant communities should support each other
as they grow through various stages, i.e. Natural Herbaceous Plant Selection
otherwise known as Sustainable Plant Communities.
9. Nutrient Recycling: When plants die, they can be composted or tilled back
into the soil and used as a natural fertiliser. This not only mimics nature, but
also improves energy efficiency with little wastage.
10. Diversity: Peramculture focuses on polycultures instead of monocultures.
This stops entire crops from being wiped out by one pest/disease and
increases a crops resistance. It also has the positive side effect of increasing
By making areas/amenities, that will inevitably need maintenance, easily accessible,
you cut down on energy and time used, hence saving money. By placing zones of less
frequent activity in well lit areas you can even reduce vandalism (Lamb, 2008). By
using nitrogen fixing plants, green manure, self-seeders & soil binders you can reduce
the need for input of external energies (Bird, 2004).
3.4 Vandalism Controls
This section, discussing controls or preventative methods of vandalism in public spaces, will
be divided into two sections:
• Social media, &
• Physical media
3.4.1 Social Media
Social media is a term which describes the tools used to reduce forms of vandalism,
whose main cause(s) lie within social structures/environment. These forms of
vandalism include incidental & institutionalized vandalism. The practices of social
media used to curb vandalism in public spaces are: Public relation, education, rule
enforcement and co-operation (Goldstein, 1996). This form of vandalism control is
post-design and in the most part does not concern the landscape architect as it is the
local authorities that will dictate action.
Public relations or publicity campaigns
Education of staff & users of public spaces
Co-operation with the local community
Planning and integration of all these strategies is important for them to work,
for as standalone practices they are ineffective. It must be insured that the park is
heavily used. Nothing repels vandalism more than a crowded area. Areas with low
concentrations of use are perfect for vandalism, as there is less fear of getting caught,
the biggest deterrent.
3.4.2 Physical Media
While social deterrents to vandalism are mainly down to management after the design
stage, physical barriers are the domain of the landscape architect. However, the
designer must understand the social causes of vandalism & the habits of the everyday
vandal. The physical environment can also, unintentionally, install “crime features”;
factors that encourage anti-social behaviour (Goldstein, 1996).
By making it physically impossible for vandals to cause damage to their
target, one of two actions will be enacted:
1. The vandal will be unable to damage the target with their usual means and
2. The vandal will be “incited” to become extreme in their methods and
succeed in damaging the target
However, proper protection of facilities and amenities will deter most vandals.
Remember, most vandalism is impulsive, if the target is harder to destroy/vandalize, it
will take longer. This will increase the chances that the vandal will be caught by
security. The thought of this in itself acts as a deterrent in the vandals mind (Tracey,
Repair of damage facilities & amenities should also be easy, i.e. the replacing
of cracked slabs, broken trees, etc. Also, unsightly & offensive graffiti should be easy
to remove. This is where choice of materials is important to the designer. Access to
these facilities should be adequate for maintenance crews. The task of maintenance
itself should not disrupt the normal activities of the park (Christiansen, 1984). This is
where good design comes into practice.
Durable materials should be chosen for easy targets of vandals. The initial
start-up costs are easily dwarfed over time by the maintenance/repair bill associated
with cheaper/weaker materials. Stronger materials also deter impulsive vandals
looking for an easy target to destroy.
The landscape architect must choose materials that are durable, easily repaired
and still aesthetically pleasing. By making targets hard to destroy or by placing
susceptible targets in hard to reach places, vandals are discouraged from destroying
them. While vandalism cannot be completely wiped out in public spaces, its damaged
can be reduced greatly.
The tried and tested approaches of; fences, railings, walls work, but at the cost
of aesthetics. It is up to the designer to understand when and how to use them. These
structures can become overbearing and give a sense of imprisonment, or in the case of
CCTV a loss of privacy (Goldstein, 1996). Innovative ways to curb and deter
vandalism can become part of the design, because at the end of the day, the need for
fences, railings & walls is due to bad design.
There are many problems which affect the success of a design after its implementation, as
previously described. They have various causes, but these are stem from lack of
understanding and little, if no preventative methods.
Pests and diseases have plagued public spaces since their inception. Many controls
were perfected through trial and error or by simply replicating nature
(permaculture/biological control). Prevention is often better than cure in the case of diseases,
as they can spread and destroy planting systems. Vandalism has been present in public
spaces just as long as pests and diseases. Its roots lie in the local social environment and it is
exacerbated by poor design (“crime features”) (Goldstein, 1996).
Integrated Pest and Disease Control is the term given to a series of systems mutually
supporting each other. Polycultures are one of the most important features of a IPM
(Integrated Pest Management) scheme. Polycultures have a greater resistance to pests and
disease, increase biodiversity and form mutually beneficial relationships (nitrogen fixing,
repel insects) (Bird, 2004).
Controls exist in many forms, yet some are more controversial than others (chemival
vs. organic). Prevention and mitigation is only successful by understanding the problem and
environment and then implementing a system of integrated control. Very rarely will one
control work by itself (Brickell, 2002). Without knowledge of these controls & their correct
usage, public spaces will fall into disrepair.
The need, attraction and aim of controls are lowering waste, in terms of money and
labour. With restriction on funds, due to the current economic climate, the use of labour as a
control has fallen into disfavour with authorities. This has led to an increase in the practice of
organic controls & sustainable plant communities. In terms of vandalism, the inclusion of
community gardens has been used to give a sense of ownership in the local area (Vancouver
community gardens, Liz Christy Remembrance gardens New York). Also, better
understanding of layouts has been used to remove crime features (Christiansen, 1984).
Public spaces are for people. Spaces left to the ravages of vandalism and pests and
disease, develop an uninviting appearance. Left unchecked, these problems can reduce or
remove the effectiveness of design. Integrated control management is part of good design.
Pests, diseases, disorders and vandalism increase maintenance costs and degrade the image of
a public space. With the current economic climate, a client’s focus will be on keeping costs
low. Preventive, long term measures will become the epicentre of any pest, disease and
vandalism protection scheme (Bell, 2002). With greater research being developed into wall
coatings to prevent vandalism, damage to walls may soon be a thing of the past.
Problems will arise in the near future in regards to pests & disease. With cases of
resistance to chemicals increasing with fungi and insects, natural controls and preventative
measures will be focused on more intensely (Bird, 2004). The use of chemicals should be a
last resort and a sign of bad planning and design. Plants resistant to physiological disorders
(described as “power plants”) will be used to a greater degree in urban areas as pollution
increases, along with fluctuations in (clean) water supplies. In terms of pest and disease
resistance, a narrowing genetic range of ornamental planting presents a problem. With new
breeds of plants flooding the commercial market and less use of old plant breeds stocks,
ornamental plants present themselves as being more susceptible to pests and diseases
New technology, methods and research are now tackling vandalism. In Holland,
green walls are being used to cover and block walls susceptible to graffiti/vandalism. It has
also been theorized that greenery in urban spaces reduces criminal activity, including
vandalism. Water borne coatings are also being used to stop spray paints from penetrating
the surfaces of walls/structures. This allows the graffiti to be simply wiped off, or even
washed off by rain. This will significantly reduce maintenance costs associated with graffiti.
Another method (slowly) garnering support is the allocation of walled areas to graffiti. This
gives a sense of ownership to patrons of the public space. It also acts as a decoy, attracting
graffiti artists/vandals away from other susceptible areas (Tracey, 2007).
It is important for a landscape architect to understand all threats posed to a site. It is only
after analysis and understanding of plant knowledge and relevant environment can good
design follow. A thorough SWOT (strengths, weaknesses, opportunities and threats) analysis
is vital at this stage. By studying the remedial and preventive measures and controls, as
previously described, a landscape architect will be able to create an effective design with
successful implementation of protective measures (McLennan, 2004). However, knowledge
of pest and disease and vandalism controls is still only a small part of design; it still does not
guarantee the creation of an effective design.
Public spaces that have become dilapidated due to vandalism or pests and disease, are
the by-products of bad design. Proper planning and anticipation of problems are essential to
the long term success of a design. However, of all the methods described above, none would
be truly effective by themselves alone. It takes a planned integrated system of strategies and
management. Suitability, compatibility, effectiveness, sustainability and affordability are all
questions to consider and answer before implementation (Bird, 2004). All the while
complementing the design and remaining aesthetically pleasing. It is no longer a matter of
choice; it is a necessity for public spaces to maintain their intended use and appearance.
Sustainable, low energy input controls are the way forward for public spaces. These
will be integrated control schemes using several systems. The reasons for this are the current
economic climate and the use of organic controls over chemical. These systems will result in
less manual labour in terms of maintenance and an increase in biodiversity as a positive side
effect. Chemical controls have high costs in terms of materials, equipment, and labour and
can damage the surrounding environments (Brickell, 2002).
In terms of vandalism, people who want to vandalise, will do so. The amount of
damage done and cost incurred will be up to the designer. Physical barriers retro fitted into
designs upset the layout of the public space. They appear ugly and out of place. If physical
barriers are used they should be integrated and made part of the design. CCTV points are a
last resort and give a sense of danger instead of safety. With all the thought and effort put
into a design to curb vandalism, it is ultimately up to those in control post design and the
programs they implement (Goldstein, 1996).
Through working on this project i have learned and understood the problems affecting public
spaces, in context to vandalism, pests, disease and disorders. It is through this understanding
of their causes, effects & controls that I have formed my own opinion on how a landscape
architect would counter their effects and damage through design.
Personally, I believe that the use of chemicals is an admittance of bad design and poor
preparation. Chemical controls should only be used as a last resort. They pose a serious
health risk to the environment, especially in public spaces. Organic controls (i.e. companion
planting, permaculture, etc) allow for natural succession and replicate nature, making a
planting system all the more natural and less tamed, artificial. Of course organic controls
need to be designed into an integrated control scheme to be truly effective.
On the subject of vandalism, in all its forms, must be accepted to a certain degree as
inevitable. Good design can remove hotspots for anti social behaviour, yet it is up to the
local community to respect their own public space. I believe the encouragement of certain
forms of vandalism can be beneficial however. It will lead to personalisation of the public
space and give a sense of ownership to the community. These forms of vandalism include
street art and guerrilla gardening. Ultimately the best control is the public themselves. By
involving the local population in the design as much as possible, it will deter any sense of
isolation or disrespect towards the public space.
I have come to the conclusion that, in my own opinion, by understanding a site and its
surroundings (along with all its abiotic, biotic, economic and social factors) through research
and analysis, a competent landscape architect will formulate a successful design that can
stand the test of time. A landscape architect must anticipate all possible problems and
formulate their solutions to the best of his/her ability.
8.1 Design Statement
“To create an area that invites users into the space & exudes a sense of safety. The space
invites the user as an escape from the chaos of urban life”.
8.2 Design Elements and Rational
Two of the existing planting beds will be replanted with appropriate selections. These will
include pollution tolerant trees (London Plane), pest repellents (Lavender) & plants that
increase bio-diversity. These attributes will counter physiological disorders (caused by
pollution), deter disease and control pest numbers. This planting philosophy is influenced by
the practice of companion planting.
New beds will also be created in the public space. These will be cut out of the
existing concrete paving. The paving will then be recycled (up to 40%) and crushed. The
designated areas will act as a brownfield site. These beds will then be planted with sedums
and other alpines. The site will also be sown with wildflower seeds. Brownfield sites act as
important habitats for many invertebrates and birds. The diversity of the wildflower mix and
natural succession that follows will attract a high number of beneficial invertebrates to the
public space. The wildflowers will create a polyculture, becoming resistant to any rampant
disease or pest. The addition of recycled rubble from the site will increase drainage and carry
pollutants away from the soil surface (Porosity). The brownfield site creation will save cost
compared to ordering in topsoil to the site. Alpine plants will also be located in the
brownfield beds. Saxifraga urbium and Sedum acre aureum have been chosen for their
ability to thrive in poor, well drained soils.
Lighting is introduced into the design to brighten up the public space at night. The
design is also quite open and allows for clear visibility. The focal point of the design is the
raised bed/seating area.
8.2.1 Plant List
1. Platanus x acerfolia “Columbia” (Pollution tolerant) x 3
2. Craetagus monogyna x 5
3. Cotoneaster “Rothschildianus” (Tolerant of poor soil/groundcover) x 8
4. Ceanothus thyrsiflorus repens (Groundcover)
5. Lavanduala angustifolia “Hidcote” (Pest repellent)
6. Hebe “Autumn Glory” (Frost hardy/evergreen)
7. Olearia haastii (Frost hardy/beneficial insects) x 1
8. Nepeata faasenii “Six Hills Giant”
9. Wildflower mix
10. Sedum acre aureum
11. Saxifraga urbium
Banksy (2006). Wall & Piece. London: Century. p1-2, p130.
Bird, R (2004). Garden Basic: Companion Planting. London: Quantum Publihing. p12-15,
Bell, P (2002). Pests & Diseases of Horticultural Crops. Piltown, Co. Kilkenny, Ireland:
Teagasc. p2, p37-51, p56-59, p73-95.
Brickell, C (2002). The Royal Horticultural Society Encyclopedia of Gardening. 2nd ed.
London: Dorling Kindersley. p639-657.
Christiansen, M L. (1984). Vandalism Control Management for Park Districts . Available:
http://www.lib.niu.edu/1984/ip840120.html. Last accessed 4th October 2010.
Fuller, J. (2008). How Xeriscaping Works. Available: http://home.howstuffworks.com/lawn-
garden/professional-landscaping/alternative-methods/xeriscaping.htm. Last accessed 4th
Goldstein, A.P. (1996), The Psychology of Vandalism. New York: Plenum Press. p1-17, p50-
Lamb, R. (2008). How Permaculture Works. Available:
methods/permaculture.htm. Last accessed 4th
Secured by Design. (2004). Secured By Design Principles. Available:
http://www.securedbydesign.com/pdfs/SBD-principles.pdf. Last accessed 4th October 2010.
Tracey, D (2007). Guerrilla Gardening: A Manualfesto. Canada: New Society Publishers.
10.1 Plant Pests
Pest Name: Birds (Pigeons, Bullfinch, Sparrows etc)
Symptoms/Damage: Ornamentals stripped of flowers & buds. Ornamental fruit
Treatment: Remove damage fruit (Stop spread of disease/fungi)
Control: Netting &/or mechanical scarers
History/Description: While common garden birds are a welcome sight in most landscapes &
parks, they can become problematic, especially where fruit trees are involved. Their waste
can also become a slipping hazard in public spaces.
Pest Name: Cats
Symptoms/Damage: Bark damage, seed bed disruption, transplant failure
Treatment: Application of Aqua-seal 50 to bark wounds (Stop fungal/disease infection)
Control: Cat repellent spray, sonic deterrent, mesh wire netting
History/Description: Stray Cats can become problematic in public spaces damaging trees
while sharpening their claws & burning grass with urine. Deterrence & control is almost
Pest Name: Deer
Symptoms/Damage: Rose buds stripped, bark damage, new shoots damaged/eaten
Treatment: Application of Aqua-seal 50 to damaged bark
Control: Two metre high fences, mesh wire netting
History/Description: Prevalent in rural areas mostly, Deer can do detrimental damage to trees
& shrubs. They practice shaping their antlers on the bark & trample shrubs through their
Pest Name: Dogs
Symptoms/Damage: Plants uprooted, conifer root damage, lawn scorched
Treatment: Water area heavily after canine urination to combat lawn scorch effects
Control: Mesh wire fencing, deterrent dusts, repellent sprays
History/Description: Bitch urine disfigures lawns & the base of conifer trees is a location of
choice for most dogs because of its insulation values. Like cats, it is almost impossible to
control damage done by dogs, short of keeping them separated from the affected area
Pest Name: Fox
Symptoms/Damage: Lawn/Shrub scorch, conifer damage, dustbins/skips disturbed
Treatment: Water area heavily after canine urination to combat lawn scorch effects
Control: Spray repellents, Mechanical scarers
History/Description: Common in rural areas & towns, foxes are problematic. There is no
100% way to combat or deter them.
Pest Name: Mice & Rats
Symptoms/Damage: Burrows, wall damage, fruit damage, seed removal
Control: Baited traps, sonic repellent, predatory species introduction
History Description: Problematic & unhygienic, mice & rats can damage fruit & attack plants
to eat un-fallen seeds. Contact a local exterminator if rats are discovered.
Pest Name: Rabbits
Symptoms/Damage: Brown patches on lawn, shrub damage, tree bark damage
Treatment: Application of Aqua-seal 50, removal of affected lawn & replace with new turf or
Control: Individual tree guards, sonic/spray repellent
History/Description: Problem in rural areas, deterrents & controls soon lose their
effectiveness. Individual tree/shrub protection proves effective. Burrowing remains a
Pest Name: (Grey) Squirrel
Symptoms/Damage: Bulb destruction, removal of buds, shoot tip damage, tree bark stripped
Treatment: Application of Aqua-seal 50 to bark wounds
Control: Mechanical scarers, net covered cages, tree guards
History/Description: All squirrels cause damage, but none more so than the Grey squirrel.
Oak trees are quite often the victim of having their bark stripped. Also, the Grey squirrel
carries a virus that attacks the rarer Red squirrel, yet the Grey squirrel is immune to this virus.
Pest Name: Aphid (Greenfly)
Symptoms/Damage: Loss of vigour in growth, distortion of leaves/shoots, Honeydew
Treatment: Systemic Insecticide, or a safer option of insecticidal soap. May require more
than one application
Control: Application of insecticidal soap or a biological control by means of the introduction
of natural predators (Ladybird)
History/Description: Aphids are among the most problematic & commonest pests. They have
a number of species which vary in colour, but all do the same damage. Only a small amount
of plants are immune to their actions. They work by sucking the sap out of new growth in the
spring & move on to the feeding of leaves in following months. The accumulation of sap
(Honeydew) on the leaves leads to the colonisation of Sooty Mould (Secondary infection).
Pest Name: Capsid Bug
Symptoms/Damage: Holes in leaves, Brown spots on leaves, brown/withered buds
Treatment: Systemic insecticide (Bifenthrin) or insecticidal soap
Control: If identified, avoid disturbance before application of treatment. Capsids move
rapidly & spread to surrounding plants if disturbed. Better to localise the problem &
History/Description: Not as common as Aphids & rarely become as serious a problem to
require treatment. Mainly, they attack roses.
Pest Name: Caterpillar
Symptoms/Damage: Holes in leaves, leaves stripped
Treatment: Spray with insecticide (Pyrethrins) if widespread, if not, knock off the
Control: Netting, Insecticidal soap
History/Description: More common in the vegetable garden, Caterpillars still pose a problem
to urban green-spaces. They may leave shrubs defoliated & plants stripped of all their leaves,
with just the leaf veins remaining. Larvae can also be problematic.
Pest Name: Cockchafer Beetle
Symptoms/Damage: (Grub) Roots eaten, plant wilt, (Adult) Irregular shaped holes in leaves,
damage to rose buds
Treatment: Insecticidal spray (Bifenthrin), Insecticidal soap
Control: Netting, Insecticidal soap
History/Description: 4cm in size. Significant damage is caused to the plant by the grub &
adult. Tlling of the soil before planting will remove any larvae present.
Pest Name: Leaf Miner
Symptoms/Damage: Holes in leaves, weak leaves, “tunnels” visible in the leaf, occurrence of
Treatment: Minor problem, application of an insecticide is uncalled for.
Control: Remove & destroy leaves. Infected leaves must not be composted, burn leaves.
History/Description: Trees affected by Leaf Miner are Holly, Lilac, Roses, Privet,
Honeyshuckle & Azalea. “Mines” are produced by grubs burrowing their way through the
leaves, feeding until they mature.
Pest Name: Red Spider Mite
Symptoms/Damage: Red/Bronze appearance of leaves accompanied with webbing threads.
Treatment: Application of Bifenthrin every 3-4 weeks depending on scale of problem &
Control: Insecticidal soap
History/Description: Common on the underside of leaves. Prevalent on roses & conifers.
The problem of Red Spider Mites peak in warm humid weather, as the convection currents
ease their movement & spread.
Pest Name: Scale Insect
Symptoms/Damage: Loss of plant growth/vigour, yellowing of leaves
Treatment: Application of Thiacloprid in late Spring
Control: Insecticidal Soap
History/Description: Occur mostly on tree branches & large shrubs. Often hard to spot, due
to their low mobility. Often, most adults spend their entire lives in the same spot.
Pest Name: Thrips
Symptoms/Damage: Blackened leaf/petal edges, flower/leaf disfigurement
Treatment: Insecticidal soap
Control: Keep plants well watered in hot, humid weather
History/Description: Tiny, 4 winged insects. Only considered a problem where roses are
concerned. Associated with warm, humid weather. Also known as Thunder Flies.
Pest Name: Tortrix Moth
Symptoms/Damage: Curled/rolled leaves wrapped in silken threads, adjacent leaves woven
Treatment: Removal of affected leaves
Control: Insecticidal soap, protective netting
History/Description: Caterpillars roll leaves of plants together with silk threads. In this
protective shelter they feed on the leaf & plant tissues. Most active during mid-Summer.
Pest Name: Vine Weevil
Symptoms/Damage: U-shaped holes/notches on leaf edges, damage to the roots of container
plants by the grubs
Treatment: Spray with a contact insecticide
Control: Insecticidal soap, tilling of soil before planting
History/Description: Grubs are problematic with potted plants & large containers. The
adults mostly attack waxy leafed evergreens (Rhododendrons, Azaleas, Camellia). Vine
Weevil spread & move quite fast so spraying proves ineffective.
Pest Name: Wireworm
Symptoms/Damage: Roots of plants damaged/eaten, stems tunnelled through
Control: Proper soil preparation & tilling are the only way to destroy this pest.
History/Description: Located underground. Slow moving, but cause massive damage,
especially to perennials in borders adjoining grassland. Wire worms eat the roots & tunnel
their way up through the stem of the plant.
10.2 Plant Diseases and Disorders
Name: Bacterial Canker
Symptoms/Damage: Sap/gum oozing from site of infection/wound, brown circular spots &
holes on the leaves, dead branches
Treatment: Remove & destroy infected branches. Cut back branches to a non-infected area.
Spray infected trees with a copper compound from August through October.
Control: Application of Aqua-seal 50 to tree wounds
History/Description: Bacterial Canker is caused by a secondary infection. Bark wounds
become infected by the causing bacteria. Wounds should immediately be treated with Aqua-
seal 50 which blocks bacteria & fungi from infecting the wound. Affects ornamental fruit
trees (Cherry, Plum, Almond, etc).
Symptoms/Damage: Cracked, caved in bark. Bark usually shrinks around the base of an
adjoin branch. The branch will die if the canker surrounds it’s base.
Treatment: Remove infected branches
Control: Application of Aqua-seal 50, burn removed branches to stop spread of infection
History/Description: Attacks a wide range of woody plants. Can also be a problem in roses.
Name: Blossom Wilt
Symptoms/Damage: Wilting of flowers & leaves, brown discolouration, presence of grey
Treatment: Remove infected areas of the plant(s)
History/Description: Caused by a fungal infection that is preceded by a wet Spring. Serious
problem with ornamental fruit trees. Spraying proves ineffective.
Name: Bud Blast
Symptoms/Damage: Flower Buds turn brown, presence of fungus like black bristles, easy to
distinguish from frost damaged buds as they remain firmly attached.
Treatment: Remove infected buds & destroy
Control: The infection is secondary, with the primary wounds & damage being caused by
Leafhopper insects. Spraying for these insects in August with a contact insecticide will
prevent the problem.
History/Description: The disease only infects Rhododendrons. Infected buds do not rot &
are not easily removed.
Name: Clematis Wilt
Symptoms/Damage: Wilted shoots, followed by sudden death. Spreads from one infected
shoot to the other. Often area of infection is at base of plant.
Treatment: Avoid damage to the stem (secondary infections). Remove & destroy affected
History/Description: Clematis Wilt is a secondary infection caused by a fungal disease. It is
devastating to the larger flowered varieties of the Clematis family. Infection often spreads
from shots growing at the base of the plant.
Name: Crown Gall
Symptoms/Damage: Wart/Blister like growths on the lower stems & root crown. Brown in
colour, with a “bubbly” appearance. Can kill the tree if a ring of Galls is allowed to form.
Treatment: Remove the site of infection & affected area. Spray with Copper fungicide &
apply Aqua-seal 50 to the wound.
Control: Pre-treatment spray on unaffected trees in October.
History/Description: Crown Gall is a blister like formation caused by secondary infection
bacteria. The disease usually occurs on young trees in waterlogged soil. Although it can
become problematic on mature trees if a ring of Galls is allowed to form.
Name: Dutch Elm Disease
Symptoms/Damage: Defoliation (yellowing of leaves) during the growing season. The
Leaves then turn brown, but do not fall. Branches become distorted & curled.
Treatment: Cut out infected branches & burn
Control: Remove & destroy infected trees to avoid spread of the disease
History/Description: Dutch Elm Disease is a menace that spreads & kills quickly. All
infected wood/trees must be destroyed. Even if the tree is dead, the disease is not & will
spread by wind or mechanical means (animals/invertebrates).
Name: Coral Spot
Symptoms/Damage: Whitish pink spots/blisters on branches & main stem.
Treatment: Remove & destroy all infected areas
Control: Remove all dead wood from site & burn all cuttings
History/Description: Coral Spot is a fungal disease that enters the plant through an open
wound. However, the fungus begins life by colonizing fallen dead wood &/or cuttings on the
ground. From here it spreads to leaving trees & shrubs. The disease can prove fatal to plants.
Symptoms/Damage: Wilted, brown leaves that do not fall. Presence of Canker on the
Treatment: Remove infected branches, plus 60cm of healthy branches to avoid spread.
Control: Burn all cuttings, dead wood & fallen trees. Contact the appointed government
authority (Coillte, Teagasc). Destroy surrounding trees you suspect of infection.
History/Description: Fireblight is a destructive & easily spreadable disease. It is mandatory,
by law, that you contact the local government authority if you suspect Fireblight. Fireblight
mainly affects trees & shrubs of the Rose family, but truly, no plant is safe. Fireblight
spreads by bacteria in the wind. If infection spreads from the branches to the main
stem/trunk, the tree will die. Dead trees & cuttings infected by Fireblight must be burned in
an effort to halt or at least, slow down the spread of the disease.
Symptoms/Damage: Plant death, undeveloped leaves, die back, blackened roots
Control: Burn infected plants, Improve soil drainage
History/Description: A soil borne fungus occurring in waterlogged areas. The fungus infects
roots near the stem of the plant & from there infect other roots & eventually other plants.
There is no treatment for the disease. Waterlogged sites should be avoided & the soil
amended before use.
Name: Powdery Mildew
Symptoms/Damage: Leaves covered in a fine, white, patchy powder.
Treatment: Cut out affected areas
Control: Avoid overplanting in small spaces
History/Description: Common in moist, warm, humid weather. Spreads easily in
overcrowded plant beds. Usually, it is not fatal to the affected plant.
Symptoms/Damage: Yellowish brown blisters on the underside of leaf
Treatment: Spraying proves ineffective
Control: Remove & destroy infected areas
History/Description: A non-fatal disease. It affects Birch, Rhododendrons & Mahonia. The
blister(s), on the underside of the leaf, produce spores that spread the infection.
Name: Shot Hole Disease
Symptoms/Damage: Appearance of brown spots on the leaves, which then fall out leaving
Control: The attacking fungus is only problematic on weakened trees. Avoid this by feeding
& regular care. Burn fallen leaves to hinder the spread of the disease.
History/Description: Shot hole disease becomes a problem on ornamental cherry trees. This,
however, can easily be avoided by providing the conditions it needs to grow strong. The
brown holes in the leaves are dead parts of the leaves. As the leaf grows, the dead spots do
not. The infected areas fall from the leaves. This is how the fungus spreads.
Symptoms/Damage: Variegated leaves, blotchy yellow spots, streaked flowers, stunted
growth & crinkled leaves
Control: Keep aphids to manageable levels, as they carry many viruses.
History/Description: Viruses is a generic term for the many diseases that fall under this
sector. Few shrubs & trees are susceptible to infection. Yet, there is no cure for the ones
who are. Some plants are purposely infected by viruses by growers for aesthetic reasons, i.e.
Symptoms/Damage: Accumulation of green black slime on the surface of lawns.
Treatment: Ferrous (Iron) Sulphate
Control: Aerate soil in Early Autumn & topdress with Lawn Sand.
History/Description: Algae growth on lawns is a clear indicator of poor drainage. Algae
appears alongside areas of moss & along the “Drip-Line” of trees. Applications of lawn feed
can give lawn grass a competitive advantage to occupy optimum sites for Algae growth.
Name: Dollar Spot
Symptoms/Damage: Circular brown patches on lawn
Treatment: Application of a high Nitrogen fertiliser
Control: Aerate soil in early Autumn
History/Description: Dollar Spot is a fungal disease that affects Creeping Red Fescue &
other fine leaved grasses. The circular patches eventually join together & destroy the
appearance of the lawn.
Name: Fairy Ring
Symptoms/Damage: Rings of dark green grass appear, surrounding a circle of dead, brown
grass. Most fairy rings are accompanied by mushrooms.
Treatment: Application of a high Nitrogen Fertiliser. This only masks the problem, as it
darkens the surrounding, unaffected grass.
Control: Removal of topsoil from affected area.
History/Description: They’re several types of Fairy Rings, each with varying degrees of
impact. There are no treatments or cures for fairy rings. Complete turf replacement is the
only effective method.
Name: Fusarium Patch
Symptoms/Damage: Round yellow patches appearing on the lawn. Presence of white mould
at edges of infected area.
Treatment: Application of Nitrogen rich fertiliser
Control: Aerate soil in early Autumn
History/Description: The most common disease of lawns. Occurs in Autumn &/or Spring.
Nitrogen rich fertilisers must not be applied in Autumn.
Name: Red Thread
Symptoms/Damage: Appearance of bleached patches, which turn pink.
Treatment: Application of high Nitrogen fertiliser in Spring
Control: Soil aeration
History/Description: Occurs in irregular patches on starved, nutrient deficient lawns.
Unpleasing to look at, fortunately it is non-fatal.
Symptoms/Damage: Yellowing of leaf tissue. Either between the veins (Magnesium
deficiency) or the entire leaf (Iron/Manganese deficiency)
Treatment: Application of fertiliser & peat (improves drainage)
Control: Proper soil drainage management
History/Description: Many forms of Chlorosis exist, each caused by a lack of certain
Macro/Micro nutrients. Lime induced Chlorosis occurs in Acid loving plants growing in
Name: Nitrogen Deficiency
Symptoms/Damage: Small, undeveloped, pale leaves
Name: Potash Deficiency
Symptoms/Damage: Brown leaves, which are very brittle. New shoots turn downwards.
Name: Manganese Deficiency
Symptoms/Damage: Browning between leaf veins
Treatment: Application of 10:20:20 fertiliser & well rotted manure.
History/Description: Low Cation Exchange Capacity (C.E.C.) in soil causes vital nutrients to
be washed out of the soil by heavy rain. Improvement of soil structure is the only long term
treatment. Manganese deficiencies are often caused by high levels of Potash in the soil.
10.3 Companion Planting
Name: Chamaemelum nobile
Attribute: Attracts Hoverflies, Wasps
Controls: Aphids, Blackfly
Name: Hedera helix
Attribute: Attracts Hoverflies, Wasps
Controls: Aphids, Blackfly
Name: Helianthus species
Attribute: Attracts Lacewings, Wasps
Controls: Aphids, Blackfly. Also acts as a Decoy plant, drawing several pests away from
planting susceptible to pest damage.
Name: Tagetes erecta
Attribute: Repels Nematodes
Controls: Reduces damage to planting
Name: Tagetes patula
Attribute: Repels Nematodes
Controls: Reduces damage to planting
Name: Solanum nigrum
Attribute: Poisonous, attracts adult Colorado beetle to lay its egg around plant roots. Acts as
a decoy plant.
Controls: When eggs hatch, the larvae eat the poisonous roots of the plant, reducing the
number of Colorado beetles in the vicinity
Name: Allium schoenoprasum
Attribute: Cures Blackspot on Roses, repels Japanese beetles
Controls: Disease, Japanese beetles
Name: Anethum graveolens
Attribute: Repels aphids & red spider mites
Controls: Gall disease on trees on woody shrubs, which is manifests after primary wounds
caused by red spider mite
Name: Eucalyptus species
Attribute: Repels broad range of insect pests (& predators)
Name: Allium sativum
Attribute: General insect repellent
Name: Tropaeolum majus
Attribute: Repels aphids, Colorado beetles & Whiteflies
Controls: Reduces local pest population
Name: Rosemarinus officinalis
Attribute: General insect repellent
Name: Salvia officinalis
Attribute: Repels root maggots
Controls: Reduces damage to root systems of plants
Name: Lavanduala species
Attribute: Repels Aphids
Controls: Reduces local Aphid populations
Name: Thymus vulgaris
Attribute: Repels Whitefly, Aphids
Controls: Protects local planting system from pest damage
Name: Medicago sativa
Attribute: Acts as a Decoy plant
Controls: Lygus bugs
Name: Chenopodium album
Attribute: Acts as a Decoy plant
Appendix C (Problems of Vandalism)
Rate of Occurrence: Common
Areas Affected: Smooth surfaces, Walls, Structures
Solution: Paint over affected area, Pressure wash affected area clean
Prevention: Use Rough Textured walls, Treat walls with a water borne coating, Green
Name: Tree Damage
Rate of Occurrence: Uncommon
Areas Affected: Pathways, Planting systems
Solution: Replant/repair tree, prune damaged branches, application of Aqua-Seal 50
Prevention: Fencing off tree