Session Notes: Sustainable Garden Design

Food

Organic Potting Mix for Vegetables – Phil Dudman

2 x 9l buckets of good quality potting mix
1 x 9l bucket of garden compost
A few good handfuls of coir/coco peat
2 scoops (400g can) pelletised chicken manure
½ scoop blood and bone
A good pinch of trace element mix / rock dust
Mix it all together on a bench and you’ve got a truly magical blend
Keep soil moist and treat the potted veggies to liquid fertilizer every fortnight

What is a Sustainable Gardening?

Sustainable Gardening is about – being part of the wider ecosystem – the environment and working with it; practising closed loop gardening with your resources; taking positive climate action in your patch; connecting into the gardening community. It’s about how garden, just as much as it is about what you garden

What is a sustainable garden?

Can be many things: Food Garden, Wildlife Garden, Thrifty Garden, Climate Action Garden, Community Garden, street garden.

Know your gardens micro climate

These are created by sun, shade, temperature, rain, wind, humidity and will determine what plans you need to put where.

Summer Sun and Shade
Veggie Gardens need 6 – 8 hours of sun, especially in winter so afternoon (western) shade can be beneficial in winter but in summer try:
Using deciduous trees and vines (especially on the western side)
Adding shade structures
Choosing drought tolerant plants

Wind Protection
Hot northerly winds can dry and damage plants; Plants may require extra watering on windy days; Wind on elevated sites can be especially intense; Avoid solid windbreaks as these can strengthen winds. Use wind tolerant plants instead.

The “Whole of Environment” Garden.
We need to look at our garden as a part of nature and tis natural cycles and patterns
Our gardens are an ecosystem and a food chain.

Wildlife Gardening

What does it do?

Keeps soil moist for longer
Provides habitat for insects, lizards ect.
Suppresses weed growth
Adds nutrients to the soil and improves soil structure
Reduces run-off and erosion
Keeps soil friable with reduced compacting
Regulates soil temperature

Wildlife Gardening Resources

Food – Leaves, fruit, seed, insects etc.
Shelter – Dense shrubs, prickly bushes, rock crevices, tree hollows, grasses
Fresh water – Ponds, gullies, depressions, rock pools, water bowls etc
Breeding sites – Trees, thickets, grasses, leaf litter, rocks and tree hollows, water etc
Prevent soil erosion – plant plants, mulch

Garden Structure and Diversity

Open gardens provide little food or shelter
Think in 3 dimensions and build vertical and horizontal layers in your garden
The more layers and variety of plants, the more diversity it will attract and support

Canopy – Large Trees
Mid Storey – Small Trees and shrubs
Understorey – Small Shrubs
Ground Cover
Leaf letter, rocks and logs
Soil fauna

Indigenous Plants

Are suited to the local soil / climate and can thrive with low rainfall
Help preserve the local plant ecology and contribute to the distinctive character of the area
Indigenous wildlife has evolved with these plants that provide perfect habitat, shelter and food
Symbiotic relationships between indigenous flora and fauna, especially in the bug world
Enhances wildlife corridors and provides habitat steppingstones between fragmented and otherwise isolated communities
If your soil is relatively undisturbed, no need to do too much work on amending the soil
Keep you compost for the veggie garden

Ground Preperation – Sheet Mulching or Solarisation

Choose your plants

Autumn to Spring is the best time to be planting new plants
Tube stock are cheaper and often grow quicker than larger potted plants
Choose healthy plants and not root bound
Squeeze the pot to see if gives (loose) or resists (root bound)

Soak pots before planting

Ensure the plant is moist before planting
Soak in water with some seaweed solution

Dig a hole

Remove weeds from around the hole
The hole should be 2 to 3 times wider that the pot
Keep soil for backfill. Break up large clumps. Can use potting mix if the soil is poor to help establish the plant
Make sure there is some loose soil in the bottom of the hole
Check hole drainage by filling with water. If too slow to drain (>4 hours) may have to amend the soil or find another location.

Remove plant from pot

Carefully remove the plant from the pot
If it is hard to get out, tap or squeeze the sides
If the roots are dense / twisting around the shape of the pot, gently tickle to loosen

Place in the hole

No need to add nutrients/conditioners
Gently place the plant in the hole
Ensure the plant isn’t too deep.

Backfill and water

Gently push soil back around the roots of the plant and push down firmly
Do not compact the soil (no standing on it)
Make a little moat around the plant to capture water
Give a good soaking water

Potentially install a plant guard to protect from wildlife

Plastic, corflute or mesh

Mulch

Chunky bark/wood chip mulch
Not around the trunk

Maintain

Water for first 6-12 months to establish
Remove weeds
Prune after flowering
Refresh mulch

Organic Mulch

What does it do?

Keeps soil moist for longer
Provides habitat for insects, lizards etc.
Suppresses weed growth
Adds nutrients to the soil and improves soil structure
Reduces run-off and erosion
Keeps soil friable with reduced compacting
Regulates soil temperature

Which Mulch? Tree Mulch of Indigenous Garden

Ground Cover Mulch

Chunky with minimal fine particles
landscapers/native mulch
Slowly breaks down to release nutrients
Good water penetration
Good air exchange
Keeps soil moist
Suppresses weeds
Reduces run-off and erosion
Regulates soil temperature
Keep soil friable
Reduces compaction
Provides habitat for insects, lizards ect

Soil Conditioning Mulch

A high level of fine particles
Breaks down relatively quickly to feed the soil foodweb
Sometimes up to 70% consumed in first 12 months, then 50%, then 30%
Improves soil structure when decomposed
Reduces run-off and erosion
Regulates soil temperature
Can become a substrate for weed growth
Lets less moisture through

Reduce Chemical Usage

A “Whole of Environment” garden is in balance and has inbuilt pest control
Many native birds, lizards, micro-bats, insects are the natural predators of pests
Insects that have been sprayed with poisons can be harmful to wildlife that eat them
SGA’s “Garden Product Guide” identifies garden products that have a low environmental impact rating
Use Intergrated Pest Management – IPM
Pest Repellent Plants – Penny Woodward

Be a Responsible Pet Owner
Obey local government by laws and contain your animal on your property; Fence off areas such as frog ponds from dogs and cats; Secure dogs and cats, especially at night, so they don’t prey on native animals

Bird Baths
Ensure your bird bath is: Off the ground – suspend from a tree or on a pedestal, Clean – water replaced regularly & has no detergents, Placed in dappled shade, Shallow with a rough bottom or pebbles or a stick, Relatively exposed so birds can see approaching danger but close to safety

Supplementary Feeding – Recommendation is to not supplementary feed.
Increases wildlife dependence on us; Can be an unnatural / unbalanced diet; Exposes them to more disease; Decreases foraging / gleaning skills increasing vulnerability if food runs low; Interrupts migratory behaviour; Wildlife breeds up to a level of food resulting in population booms ; Can decrease diversity by favouring dominate, aggressive species; Attracts unwanted pests / rodents; Can makes birds vulnerable to predators.

Food Gardening

Starting Your Veggie Garden
Grow food like nature does; Feed the soil-food-web; Avoid synthetic chemicals; Compost your organic waste; Encourage garden resilience by growing a diversity of plants; Encourage beneficial insects; Capture rainfall and use water wisely; Include a place for yourself

What do I need for a Veggie Patch?

Good sun exposure – Northerly or westerly aspect
- Fruiting Veggies – min. 8 hours / day
- Root Veggies – min. 6 hours / day
- Leafy Veggies – min. 4 hours / day
Open friable soil with good organic content; Access to clean water; Compost / vermicast / worm tea; Straw based mulch; Good air circulation

Raised Garden Beds

Can be adapted to any area, even hard surfaces
Great for growing veggies
Saves your back
Choose a level spot with full sun
Permanency? Moving it will be difficult
If it has a base – ensure there are adequate drainage holes
If hollow – line with layers of newspapers / cardboard

Productive Potting

Using the right pot – big is better
A sunny position – 6 to 8 hours Will the location be too hot, too windy, or reflect heat?
Place where you will remember to water regularly
Good potting mix (ticks)
Regular water at the soil level
Liquid fertilizer e.g. compost / worm teas
Add straw based mulch to reduce evaporation, protect soil

Good Veggies for Pots: Tomato, eggplant, capsicums, cucumbers, asian greens, salad greens, beetroot, potato, bush beans and peas, carrots

Grow your own herbal teas: sage, chamomile, stevia, lemon verbena, thyme, mints, rosemary, lemon balm

Soil Structure
Sandy – Poor water holding ability / Excellent drainage; May be hydrophobic; Poor structure; Leaches nutrients; Easy to cultivate; no structure
Clay – Good water holding ability; Good nutrient retention; Poor drainage; Low aeration; Poor root penetration; Difficult to cultivate
Loam – A combination of fine and coarse particles; Good water holding ability; Good drainage; Easy to cultivate; Good nutrient holding ability
The best way to improve Soil Structure – Add organic matter

Soil Chemistry – pH

pH is expressed in terms of acidity and alkalinity and has a role in:
A plants ability to access and use nutrients
Soil microbial activity
pH range for most garden plants is 6.0 to 7.5
Use a simple pH test kit (available from nurseries) to test the pH of the soil

Adjusting pH

The best was to balance the pH of soil – Add organic matter
If the pH is too low (acid), it can be raised with Garden Lime
If the pH is too high (alkaline), it can be lowered with garden Sulphur (slow to amend)

Soil Biology – Soil Food Web

A universe of unique and diverse organisms that live in the soil and recycle energy, carbon and nutrients
The best way to feed the Soil Food Web – Add organic matter

Party or Game of thrones

One teaspoon of good garden soil contains one billion bacteria of between 20,000 and 30,000 species, several yards of fungal hyphae, several thousand protozoa and a few dozen nematodes?
Teaming With Microbes – A Gardener’s Guide to the Soil Food Web

Activate the Soil Food Web

Add organic matter: Feed the soil food web; Compost, manure, mulch, leaf litter; Plant cover / green manure crops
Avoid garden chemicals: Fertilizers, pesticides, insecticides etc.; Disrupts the Soil Food Web and / or kill microorganisms; Implement Integrate Pest Management
Keep soil moist: Add organic matter; Mulch Mulch Mulch; Creates a good habitat for the soil microbes; Provides water for plants
Minimise Digging; Exposes soil life to UV light; Disrupts Soil-Food-Web; Destroys cavities, created by burrowing critters, for air, water & nutrient cycling
Avoid soil compaction: Destroys cavities for air and water; Avoid stepping on garden beds; Avoid heavy equipment on garden beds; Keep beds an arm reach in width
Prevent soil erosion: Soil-food-web is most active in top 30cm; Mulch / Mulch / Mulch; Always have plant cover

Soil Nutrients

Edible gardens need lots of nutrients
Existing soil nutrients can be made more available by regulating soil pH
Supplement soil conditioners with organic fertiliser
Soil conditioner: Food for the soil; Slow release; Bulky organic additives; Macro / micro-nutrients and trace elements
Plant fertilizer: Food for the plants; Quick boost for hungry veggies; Macro-nutrients – NPK

Feeding the Patch

Soil Conditions: Compost; Vermi-castings; Worm tea; Matured animal manures (cow, sheep, alpaca)
Fertilisers: Blood and Bone (N); Chicken manure (N); Nettle tea (N); Pelletised manures (NPK)
Note: Leafy greens = N; Fruiting / rooting = NPK
Other: Seaweed Solution; Comfrey tea; Rock dust; Dolomite Lime; Crushed eggshells

Best Mulch for Veggie Patch

Pea straw / Lucerne / Sugar cane
Avoid hay as it will contain seed
Avoid bark mulch in the veggie patch
Soil should be moist prior to mulching
Add mulch after spring rains, before summer drying
Apply no thinner than 25mm
Apply no thicker than 75mm

Why Recycle Organic Waste at home?

Reduce Emissions
Feed the Soil Food Web
Improve Soil Structure
Add Soil Carbon & Humus
Grow Healthy Plants

Recycling Organic Waste: Worm Farming; Composting; Bokashi; Chickens

5 Key Ingredients

Browns / Dry Inputs / Carbon – Leaf litter, Dead plant material, Twigs, Leaves, Straw, Shredded newspaper or cardboard
Greens / Wet Inputs / Nitrogen – Fresh plant pruning’s and garden waste, Household food waste, Tea leaves, Coffee grinds, Animal manure
Water – Composting organisms need moisture, but not too much. Moisture from your kitchen scraps should generally be sufficient. The compost should feel damp but not wet Damp Sponge. If too wet, add more dry ingredients
Oxygen – Aeration is required to ensure oxygen can enter the compost. Oxygen is required so the aerobic bacteria can breathe. Turn the compost weekly to add oxygen
Layering – Use thin layers (3-10cm), Alternate green and brown. Use a diverse range of materials

Avoid Garden Chemicals!

You can successfully grow food without the use of chemical based pesticides and fertilizers
Many insects in the garden e.g. ladybirds, are ‘good guys’ that will hunt and eat pests such as aphids
If you spray lots of chemicals in your garden, you will kill these beneficial insects and make your pest problem harder to control
Use natural alternatives such as chili and garlic spray to control pests

Integrated Pest Management

Mechanical Pest Control – Hand Removal (snails); barriers (netting, fencing, copper tape); Traps (Beer traps, pheromone traps, sticky traps)
Cultural Pest Controls – Remove pest habitat from garden; Crop Rotation
Encourage Biological Good Guys – Companion Planting. If you have been using chemical controls in your garden, it will take some time for beneficial insect numbers to increase, so be patient. Remember, without any food, beneficial insects won’t survive either, so you must be able to tolerate a low level of insect pest damage.
Chemical Controls – Last Resort. Think about homemade remedies first:
- Garlic-chili sprays – leaf attackers, Milk sprays – powdery mildew, Botanical oils – aphids/scale
- As a last resort – use a low impact chemical solution.
- Check the SGA website for recommendations

Habitat for Beneficial Insects

Beneficial insects include:
- Pollinators such as bees (native and honey), hover flies
- Predators include ladybirds, lacewings, hover flies, praying mantids, spiders and predatory mites
- Parasitoids of pests such as wasps

Plants to Attract Beneficial Insects

Open and densely floiwering plants are excellent attractors of beneficial insects:

Carrot Family (Apiaceae/Umbelliferae)	Dense flowers arranged in umbels Particularly good for parasitic wasps	Dill, parsley, anise, garden angelica, caraway, chervil, lovage, coriander, cumin, fennel, carrots, celery, parsnip
Daisy family (Asteraceae/Compositae)	Shallow open flower Popular with lady birds, lacewings, spiders, hover flies and wasps	Absinthe, artichokes, chamomile, tansy, cardoons, chicory, tarragon, fever few, dandelion, yarrow, black-eyed Susans, anthemi, cosmos and salsify

Water Application

Water should be delivered directly to the plants root zone, preferably in the early morning
Use water efficient systems
For soil / ground gardens
- Water more thoroughly, less often
- encourage development of deep roots, increasing drought tolerance
For container / pot garden
- Water sparingly, more often
- Water coming out of the bottom is a waste and a loss of vital nutrients
- Place a saucer or container under the pot to collect water
Above – Sprinkler / Hand Sprinklers – A very inefficient way of watering a garden
(Sub)Surface Irrigation – Drip Irrigation – A very efficient way of watering a garden
Irrigating from Below – Wicking Beds