Australia Weather News

With spring off to a warm start and weather experts tipping another hot summer, it's a good time to start preparing your garden for the heat.

Rather than waiting until summer hits, a little work now — and knowing a few things to avoid — can help stop your plants getting crispy.

Perfecting your mowing technique and laying mulch are just some of the easy jobs that experts recommend tackling.

Don't squash your soil

A simple thing you can do in the months ahead of summer is avoid compacting the soil on wet days, says Naarm/Melbourne-based horticulturalist and Sustainable Gardening Australia community training manager Liz Rowe.

"If we can reduce how much we're compacting, that's going to leave those air pockets available for water to fill it in [in the future]," she says.

"Stick to paths or … if you have to step into your veggie beds or your garden beds, put a board down."

Ms Rowe says the aim is to capitalise on any rain your garden is getting before the heat hits.

"If we compact our soils, the water's not going in there — it's just going to flow away. So … reducing compaction is going to be one of the first big steps."

Avoid digging and top-dress

Top-dressing your garden can also aid soil health and water retention, Ms Rowe says.

"You could do a compost or manure layer," she says.

"We because … the microbes and bugs will do a lot of that work for us.

"They're burrowing or creating air pockets as well, which is going to help our water-holding capacity and infiltration in the long term.

"The more we till or turn our soils, we're actually killing off a lot of the beneficial life … that is going to help drought-proof it as well."

If your soil needs aeration, Ms Rowe says a broad fork will do the job with no turning.

Get mulching

A good layer of mulch on top of the soil also helps conserve water and prevent evaporation, says Australian National Botanic Gardens director Matthew Parker, from Canberra/Ngunnawal and Ngambri land.

Choosing the right mulch depends on what your garden looks like, according to Ms Rowe, who says outdoor plantings generally fall into three categories: perennial beds, annual beds and pots.

"In our perennial beds (with plants you don't need to replace every year, such as trees and shrubs), we often advise leaning towards wood-based mulches [such as woodchip]," Ms Rowe says.

"And straw [or hay-based] mulches, which are a lighter organic option … we prioritise those on our annual beds (with plants that need swapping out every year, such as vegetables or cut flowers)."

Pots can be mulched with "almost anything", she says, adding the most important thing is its capacity to reduce evaporation without cutting off the soil's access to water and air.

Dr Parker says the depth of your mulch is also important, and 70–100 millimetres is idealfor a garden bed.

"It needs to be a decent thickness that will effectively create a mat or a barrier to limit evaporation," he says.

However, Dr Parker warns wood-based mulches may not be a good choice for areas with high bushfire risk.

Cut your grass longer and avoid pruning plants

Dr Parker also recommends increasing your turf height by adjusting your mower to help protect the lower parts of the grass from the sun.

"If people are cutting the grass really low, then that's going to increase the stress on the plant," he says.

Similarly, he says you should avoid hard-pruning your plants in the lead-up to a heatwave.

"Often people think that the plant's going to be losing water, so it's better to prune it and reduce the size of the crowns," he says.

"But … pruning and removing branches can create additional stress."

Create shade

If your gardening budget is a little bigger, you could also consider creating some shade.

"If you have a veggie plot, you might be able to put a shade cloth over the top to reduce the intensity of the UV," Dr Parker says.

"The leafy [vegetables] over summer need a lot of water. But installing some shade … would be useful, particularly during those peaks of the heat waves."

Set yourself up for watering

Setting up irrigation lines with timers ahead of summer is also an option.

"The gold star that's often recommended is your drip-line irrigation, but these things cost money," Ms Rowe says.

"But you could also look at a [cheaper] trickle hose on a timer."

Once the heat hits, both experts say early in the morning is the best time to water the garden, before the sun is at its hottest.

Protect your pots

Potted gardens tend to be more vulnerable to the heat, but Ms Rowe says grouping them together can help protect them.

"If we can group our plants together based on their water needs, it makes it easier for maintenance, but … they can also insulate one another and help cool each other down," she says. 

If your plants are in plastic pots or containers, she suggests using a ceramic pot as a "sleeve", but says other vessels — for example, a Styrofoam cooler box — can be just as effective.

"Putting them inside something else that's going to insulate around the root system can help," Ms Rowe says.

Dr Parker says shifting your potted plants to a shaded area ahead of a heatwave can also help.

Choose the right plants

And although it requires some forward thinking (sometimes years in advance), planting heat-tolerant species appropriate to your area, such as local natives, is the ultimate way to help your garden survive hot weather.

"Consider the types of plants that you're growing and check that they're suitable for the environment," Dr Parker says.