Protected growing in practice - IPM, light controls, and specific plants.

1. RHS Level 2
Certificate
Year 2 Week 13 – Integrated
Pest Management, Containers
and Specific Plant Raising
Techniques

2. Learning
Objectives
4.6 Describe the importance of cultural and biological
controls to limit the damage caused by plant pests
and diseases
Know the types of container used for production and
display in protected environments.
5.1 Compare the properties and characteristics of
materials used in the manufacture of plant containers,
including terracotta, plastic, polystyrene, peat, paper,
natural and reconstituted stone, and recycled
materials.
5.2 Describe the factors that should be considered
when choosing containers for the display of plants in
greenhouses and interior displays, including
management considerations and visual appeal.
6. Understand the horticultural uses of the protected
environment.
6.1 Describe the use of protected environments for the
over-wintering, production and display of plants.
6.2 Describe the production of a range of plants which
can be grown in a protected environment in a garden
situation under the following headings: propagation
and establishment; maintenance; control of pests,
diseases and disorders.

3. Quiz -
answers
1. Carbon dioxide + water + Light → glucose
+ oxygen
(when in the presence of Chlorophyll)
2. Because the rate of the reaction is
restricted by whichever factor is in
shortest supply.
3. Orientation, site (no shade), cladding
material, thickness of glazing bars, time
of year, cleanness of cladding
4. (d)
5. Protection from blight; extended
growing season
6. Spraying water onto the floor and
structure of the greenhouse
7. Raises humidity and lowers temperature
8.The RH will fall.

4. Integrated Pest Management
Why? - Pests are becoming resistant to
chemicals; chemicals are expensive and
dangerous to the operator; chemicals are
being withdrawn from sale.
What? To combine prevention of pests and
diseases with biological and cultural controls,
using chemical controls as a last resort and
only when and where needed.

5. Integrated Pest Management – How?
Prevention – grow
resistant varieties
where available; good
hygiene; growing strong
healthy plants;
controlling ventilation
and humidity.
Monitoring – regular
inspection for signs
of pests or diseases
and taking prompt
effective action when
seen.
Biological controls –
using ‘good bugs’ to
control ‘bad bugs’
Chemical controls –
using the least
harmful control and
treating only the
infested plants or
areas.

6. IPM – advantages and
disadvantages
Advantages Disadvantages
Effective against pesticide
resistant pests
Need a population of pests
before biological control
used
Higher health crops due to
monitoring and prompt
control
Can be more expensive
Lower chemical inputs – so
little ‘harvest interval’ delay
Needs well trained staff if
used commercially
Safer for operators Not suitable for all crops –
some damage is inevitable

7. Containers for
Protected Growing.
Materials
Plastic (pots, seed trays, etc)
Terracotta – fired clay. Can be glazed or
fired. Frost proof?
Polystyrene – used for bedding plants
etc.
Peat – Jiffy 7s or similar.
Paper – either DIY or paper-pot
honeycomb for seeds
Natural and reconstituted stone – for
conservatory display.
Recycled materials – mainly recycled
plastics.

8. Containers – advantages and
disadvantages
Advantages Disadvantages
Can grow plants that would
not tolerate outdoor
conditions
Need more watering and
other maintenance. Root
volume is a factor.
Can move containers – e.g.
to update display during
season
Not all containers are
attractive. Plastics are
short lived.
Can move sensitive
species outdoors in
summer e.g. Mediterranean
plants
Pots may overheat in
summer
Limited volume of growing
media

9. Containers – factors
influencing choice for
display
• Appearance – colour and shape can work
with the plants or against them. Can you
hide ugly pots with trailing plants?
• Watering – larger volumes will need less
frequent watering (but avoid stagnant wet
compost); terra cotta dries out quickly,
plastic retains water better. Use of hidden
water reservoirs.
• Feeding – CRF or liquid feed.
• Weight – safety in handling; load
considerations on floors with large displays.
• Suit the container to the environment and
the planting design.

10. Protected Growing - Cyclamen persicum
Maintenance – become dormant in the Summer so high
temperatures indoors will lead to dormancy. Need good
light. Water by soaking from below and allow to dry out
partially between waterings. Do not over feed.
Propagation – grown from seed, soaked in warm water,
light inhibits germination, 15°C germination temperature,
well drained growing medium essential but must not dry
out. Sporadic germination – perhaps 12 months.

11. Cyclamen persicum
– pests and diseases
• Botrytis cinerea – Mould that
attacks living plant tissues. No
chemical controls available. Do not
over water or splash the leaves and
tuber. Remove all dead or
damaged leaves and flower stalks.
• Fusarium Wilt – no chemical
control. pH above 6 limits
development of symptoms. Avoid
water stress.
• Vine Weevil – adults nibble the
leaves but the grubs do the
damage. Use biological controls or
acetamiprid (can’t use both
together).

12. Protected Growing -
Chrysanthemum x
morifolium
• Propagated from cuttings as cultivars do not
‘come true’ from seed. Softwood basal
cuttings taken March or April from
overwintered stools.
• Need bottom heat, high humidity and 21 to
29°C air temperature to root well.
• Potted 4-5 to a 15cm pot to give a good
bushy appearance. Pinched out to
encourage side shoots.
• Compost must be kept moist and air
temperature at 21°C or thereabouts. Need
good light.

13. Chrysanthemum x
morifolium – day length
• Naturally flower when day length is
under 14 hours – they are Autumn
flowering plants.
• Develop green leafy growth when day
length over 15 hours.
• Starting in April from cuttings allows
good strong plants to develop before
flowering.
• Commercial growers manipulate day
length by supplementary lighting and
black out shading to allow sale of
flowering Pot Chrysanthemums all year
round.

14. Chrysanthemum x
morifolium -
Maintenance
• Do not allow the compost to dry
out.
• Keep warm – 18 to 21°C and out
of draughts.
• Once finished flowering reduce
watering and move to a cooler
(but frost free) place. Cut off the
stems as the plant becomes
dormant. Store in moist (not
wet) compost in a frost free
greenhouse or shed until Spring.
Take cuttings from new shoots
rather than try to revive the old
plant.

15. Chrysanthemum
x morifolium –
pests and
diseases
• Aphids and whitefly are significant pests.
• Botrytis is a problem as is Fusarium Wilt.
• Western Flower Thrips cause severe damage to buds and
flowers and spread virus diseases. Controls – contact
insecticide or biological controls (could use both as part of
IPM)
• Chrysanthemum white rust - yellow spots on top of leaves
and white pustules below. Controls – systemic fungicides
and hot water treatment of dormant plants. Strict hygiene –
destruction of all affected plants.

16. Homework -
research exercise
Prepare notes on the propagation and
establishment, maintenance and
control of pests and diseases in the
following plants:
Bedding plant Impatiens walleriana
Bulb – forced for winter flowering
Narcissus ‘Tete a Tete’
Resources needed are on the web site
or you could use a gardening
encyclopaedia or other reference
books.

17. Learning
outcomes
4.6 Describe the importance of cultural and biological controls to
limit the damage caused by plant pests and diseases
Know the types of container used for production and display in
protected environments.
5.1 Compare the properties and characteristics of materials used in
the manufacture of plant containers, including terracotta, plastic,
polystyrene, peat, paper, natural and reconstituted stone, and
recycled materials.
5.2 Describe the factors that should be considered when choosing
containers for the display of plants in greenhouses and interior
displays, including management considerations and visual
appeal.
6. Understand the horticultural uses of the protected environment.
6.1 Describe the use of protected environments for the over-
wintering, production and display of plants.
6.2 Describe the production of a range of plants which can be
grown in a protected environment in a garden situation under
the following headings: propagation and establishment;
maintenance; control of pests, diseases and disorders.