1. Microclimate
Australia has a huge range of climates, and the temperature and rainfall of your area will
largely dictate what plants will thrive in your garden. In Adelaide, there can be significant
variation in climate from region to region across the city. In addition, local conditions can
vary even within a backyard. Accurately assessing your garden’s microclimate will help
you water effectively and plan your waterwise garden.
Coping with climate  The placement of hard surfaces such as paving,
Within Adelaide, temperature, wind exposure and paths or roads that may radiate extra heat;
evaporation are quite different between the and/or
coastal strip, the southern and central suburbs,  Trees, shrubs and other windbreaks.
the northern plains and the hills. Coastal areas
are warmer in winter than inland suburbs, and
cooler in summer due to sea breezes. Right plant, right place
Evaporation and temperatures drop with elevation You can make your garden more water efficient
as you climb into the hills. The northern suburbs by understanding:
are particularly exposed to hot summer winds
 How your garden features create microclimates;
because of the topography.
 How to use your garden features to your
Adelaide gardeners have to contend with a
advantage; and
Mediterranean climate with extremely hot, dry
summers and cool moist winters. Elevation also  How to modify your garden features if
affects seasonal temperature and rainfall patterns, necessary.
with some areas falling into rain shadows, Each microclimate provides different growing
particularly in the eastern and northern parts of conditions for plants. Matching plants to the
the hills. conditions they require is a major step towards
While annual temperature and rainfall variations creating a healthy and waterwise garden.
have an obvious impact on your plant choice and Expert gardeners are renowned for relishing the
water use, you should also be aware of the effect challenge of growing plants outside their natural
of your garden’s microclimate. You can greatly habitat – cold climate plants in warm climate
alter the impact of heat and evaporation on your areas and tropical’s in cooler climates.
garden and therefore reduce water needs by
However, for the average gardener, this isn’t
carefully planning and implementing key changes.
generally a good idea. Plants that are matched
with climates, and with the microclimates that suit
What is microclimate? them, will need less water and maintenance, grow
better and suffer less stress. In Adelaide this
Microclimate is the localised climate that occurs
means choosing waterwise, hardy species such
around your home. The aspect and the amount of
as local natives, succulents and cacti,
sun and shade you get in your garden, the
Mediterranean plants such as olives, rosemary
prevailing winds and the slope will all create your
and lavender and other low to very low water use
microclimate. Your garden’s microclimate is
species. Your local nursery is an excellent place
affected by:
to ask for advice, or consult some of the online
 Buildings and walls; resources listed in the ‘Resources’ section of the
 Fences and other structures; WaterRight webtool.

2. need to apply less water in this area than you
Site orientation use in your north facing area.
It’s critical to know which direction your garden  Planting shade tolerant, lush foliage plants or
faces, especially which way is north, because ferns that provide a sense of coolness, but that
that’s the direction the sun comes from. The are still waterwise. There are many species
position of the sun in different seasons and the which are suitable, such as Blechnum ferns,
patterns of sun and shade at different times of the birds nest ferns, cast iron plants and
day will have a major impact on plant choice and Monsteriosa.
water use.  Shelter vegetables in summer by creating a
A sunny aspect is a bonus if you want to grow temporary shade structure using stakes, wire
plants that require full sunlight, especially and shade-cloth. This can be rolled back on
vegetables and fruit trees. However, you may milder days and replaced when the temperature
need to use large quantities of water to maintain climbs.
plant health. Consider drought tolerant plants for
large areas with full sunlight. If you are growing Wind
more sensitive plants in full sun, be sure to shade
them using shade-cloth or a pergola featuring a Adelaide’s climate varies from season to season.
deciduous vine during the hot summer months. Particularly in the northern plains, summer’s hot,
dry westerly and northerly winds reduce humidity
You can modify the impact of aspect, but and greatly increase water loss from plant leaves
generally the northern side of your house will be due to transpiration, and from soil due to
sunnier, warmer and more exposed to the evaporation.
elements. So the best place for low water use
plants is the northern side of your house. An The rate of plant transpiration rises with an
exposed western side will also get the hot increase in temperature and wind speed, and a
afternoon sun, creating high water demand unless decrease in humidity. Plants wilt much faster on
you plant very low water use plants in this hot days, especially when the hot, dry summer
location. winds are blowing. A plant wilts in an attempt to
close its stomates and reduce water loss, but this
defence can be fatal if water is not applied.
Using shade Northerly and westerly aspects can be particularly
Shading plants that are sensitive or require extra exposed to these hot, dry summer winds.
water is your best method to reduce water needs. Windbreaks can moderate the effect of wind.
A plant in the shade can lose up to 50% less Taking note of the existing windbreaks in your
water than one in full sun. Use shade, or design garden can help you plant appropriately and
your garden to create natural shade, so the accurately calculate different areas of your
garden will be cooler and need less water by: garden’s water needs. When designing your
 Using trees, shrubs, windbreaks, climbing garden, creating windbreaks will shelter your
plants, pergolas and screens to provide shade plants and also create a more pleasant
for the garden and outdoor living areas. environment.
 Planting large trees that provide their own shady There are many different ways of creating a
microclimate. Deciduous trees can be useful on windbreak. Living windbreaks such as hedges or
the north side of the house to provide summer screening plants protect the garden from wind and
shade but let in winter light. Deciduous vines create shade and privacy. In seaside Adelaide
can be planted to cover pergolas that shade gardens windbreaks facing the coast also help
your garden in summer but allow the sun in protect your garden’s plants from salt laden winds.
winter. Some good waterwise species are If living windbreaks aren’t possible, use lattice,
ornamental pears, crepe myrtles, grapes and screens, shade-cloth or pergolas to shelter plants.
wisterias.
Windbreaks should act as a filter rather than a
 Only planting medium to high water use and/or barrier, since a solid barrier will create an area of
shade or semi-shade tolerant plants on the turbulence behind the windbreak.
south or south-eastern side of the house, which
is often shaded and moist. You will probably If you can’t moderate the wind, choose plants that
tolerate the conditions. Plants with tough, hard

3. leaves, or silvery leaves often tolerate wind. Most the south side) favoured by low water use plants
Adelaide area native plants can tolerate the that like cooler conditions, such as Dianella and
effects of both heat and wind exposure, and are Birds Nest Ferns;
worth considering if you want to create a garden
suitable to the local conditions. Visit the
Landscapes Alive Sustainable Landscapes Plant Hard surfaces
Selector for advice on plants that can tolerate Gardens are a mix of garden beds, borders and
exposed conditions. Some examples are the lawn, and hard, dry surfaces such as paving,
various Eremophilla species, Banksia species, driveways and pathways.
New Zealand Christmas Bush (Metrosideros),
Garden beds near paving or driveways that
Rosemary and native Coastal Rosemary
radiate heat will be warmer than those near turf or
(Westringia).
out in the open. Being near the road often adds
heat to front gardens. This increase in radiant
Slopes heat increases the rate of soil and plant water
loss. Large areas of hard surfaces can create
The topography and slope of your block will affect watering hot spots that require effort to maintain
the microclimate by affecting drainage patterns. plant health.
This causes wet and dry spots that will your
influence your planting schemes and irrigation Choose light coloured paving (and walls) that
regimes in different areas. absorb less heat to minimise this effect. Making
paved areas more permeable to allow rain to seep
North and west facing slopes receive more direct into soil and nearby plant roots can help save
sunlight and are more affected by prevailing water. Make paths from organic and porous
summer winds than south facing slopes. material such as gravel, pebbles, woodchips,
You can turn slopes to your advantage by placing sawdust or bark mulch, rather than using hard
high water use plants in garden beds at the paving.
bottom of sheltered slopes.
On steep exposed slopes, use low water use Constant change
plants, including appropriate natives, succulents
or other tough, waxy leafed species. Remember, plants don’t stand still, and
microclimate will always change with the seasons
You can deliberately contour a garden to redirect and as plants grow or are removed.
run-off from paths or driveways to where it is
needed or camber paths towards garden beds. Trees that cast increasing shade as they mature
may affect your watering regime, or you may have
Terracing can help prevent water waste on to prune trees to let more light into your house or
sloping blocks. onto your sun loving plants.
Avoid planting lawn on slopes as this can lead to
water loss from run-off. Instead, terrace an area to
use as a lawn and surround it with well planted, Ground cover and dense plantings
protecting garden beds. Groundcovers and densely planted shrubs and
grasses are extremely useful in keeping weeds at
bay and reducing the rate of water evaporating
Buildings from the soil. They also shelter the root system of
Buildings, walls, fences and other structures affect other plants, allowing a ‘cool root run’ which is
microclimate in a number of ways: very important for the health of many plant
 They can radiate heat to create hot spots that species. In Adelaide, covering the ground surface
may require additional watering; is of critical importance in creating waterwise
gardens. Groundcovers, or “green mulches” can
 They may block the sun to create areas of be used to reduce overall water loss from the soil
shadows and shade that require shade tolerant by reducing how much water is lost from your soil
plants and less watering; through the impact of wind and sun. Densely plant
 House eaves may create relatively dry spots your beds and minimise the area of soil that is
that don’t receive rain. This can create a hot and exposed. Ultimately this will create a garden that
dry microclimate (on the north side) suited to is low maintenance and requires far less water
cacti and succulents, or cool and dry shade (on than a sparsely planted one.