How to Heat Proof Your Garden
With the days heating up as we enter Birak, it is well and truly time to start thinking about what we can do to help our gardens survive the heat. Here are a few tips for protecting our plants and maintaining soil health, both in the coming months and in planning for next summer:
Mulch mulch mulch!
The best time to mulch is at the end of winter to lock in the soil moisture, build soil carbon and create a cooler microclimate above the soil - it's also often a time when tree loppers are likely to have an oversupply of mulch meaning it's cheap (or free - see MulchNet). The second best time is Today! Make sure that soil receives a heavy watering first however (using a soil wetting agent or compost tea if necessary) - particularly if you are using a straw based mulch as it can be difficult to rewet the soil afterwards. If you are applying a coarse mulch (eg woodchips) put some nitrogenous material down first (eg blood and bone) to ensure that the woodchips don't lock away nitrogen from the plants.
Install shade
Observe where the sun/shade is naturally falling at the Solstice (and again at the Equinox in March) and make a note of this on your garden plan. Where do shade structures or deciduous trees and vines need to go to protect sensitive plants (animals, children's play areas)? Some of these might be permanent, some may be seasonal (ie 30% shade cloth on sun-tender berries and vegetables over summer), others may be temporary structures using old sheets (these can be wetted to create a "Coolgardie safe" effect), net curtains, shade cloth etc from op shops on the hottest days.
Rethink water
How effective is your watering? Consider converting fine misters to heavier droppers, bubblers or drippers. Can you make use of greywater? Can you introduce Ollas or else install vertical pvc pipe to deliver water to the root zone of young fruit trees? Can you install a wicking bed or convert existing beds into wicking beds? Can you make use of runoff water (ie from airconditioning units, outdoor showers)? Can you install a pond to create a cooler microclimate?
Rethink when and where to plant
As summers increase in intensity is it possible to plant our summer crops earlier (protecting seedlings from frost and hail and increasing soil warmth by use of cloches or mini greenhouses if necessary) so that we aren't trying to nurse them through the hottest months of summer. Is it possible to contract our summer gardens back to a smaller, more intensively managed area (maintaining soil health elsewhere through use of heat tolerant summer cover crops)? Or to plant precious plants into containers or garden beds on casters that can be moved into more shade on extreme heat days?
Heat proofing our communities
Often we approach these problems individually - but what can we do as a community? Recent research suggesting that Perth is likely to experience between 2 and 3 times as many days over 35 degrees in the coming decades than we currently receive depending on CO2 emission scenarios and fossil fuel reduction targets. What can we do collectively to advocate for a cooler, greener city and for more liveable neighbourhoods?
This article written by Yann Toussaint.
