How to protect your garden against heat stress

Garden protection kit

The soaring temperatures and harsh UV rays of high summer can cause plants to wilt and burn. Fortunately, there is plenty you can do to protect them and help them survive the heat.

Throw some shade

One of the best ways to provide relief from the intense sun is to install a shade cloth. “Look for one with a 30 to 50 percent shade rating and erect it over vulnerable plants,” says horticulturist Angie Thomas of Yates. Create a frame using stakes or star pickets, which allow you to easily install or place the cover over the plants. “Shade cloth is particularly handy in the tomato patch, as fruit is susceptible to sunburn if not protected,” adds Angie. Move potted plants to a shadier spot or set up a sun umbrella to keep them cool.

Dig deep

Over time, soil and potting mix can become hydrophobic (water repellent).“Apply a wetting agent to help break down the waxy, water-repellent layer and allow the water to penetrate into the root zone,” says Angie. A hose-on pack is a good option for large areas like the lawn. 

Improving the soil with organic matter can also help increase its water uptake. “Organic matter like compost and composted animal manures act like a moisture sponge in the soil,” says Angie. “Mix them into the soil at planting time and reapply regularly through the year.” 

Revisit your watering routine 

Wilting leaves are a sign plants are suffering from a lack of water, but you don’t necessarily need to water more – it’s about when and how. “It’s best to water deeply a few times a week instead of watering in small amounts every day,” says Angie. “Thorough watering moves the moisture deeper into the soil, which promotes deeper root growth and helps plants cope better with hot and dry conditions.”  

Hand watering is easy, but time-consuming, says Matt Wichmann of Holman. “Hoses and watering cans are ideal for small balcony gardens, pot plants and targeting specific areas, but for those with larger spaces or lots of plants, consider installing irrigation.” A black poly pipe with drippers is very effective. “Set it up so it waters the root zone directly. This will help maximise water efficiency and minimise run-off and evaporation,” says Matt. “Add a tap timer to automate the whole system.” 

Take advantage of mulch 

Mulch is garden gold. “It keeps the soil cool and reduces moisture loss,” says Angie. Organic mulches like pea straw, lucerne and pine bark are great because they add organic matter to the soil as they break down. Straw mulches can be applied up to 10cm thick, but keep bark mulches between 5-8cm. Don’t forget to mulch pots, too. Inorganic mulches like gravel and stones also work, but they don’t add anything to the soil.  

Don’t mow too low

The golden rule with lawns is to never mow more than one-third of the length off your grass. Why is this so important in the hot season? Long blades of grass provide cover and shade for the soil, so the roots stay moist. 

Some like it hot

“If you live in an area with hot, dry summers, look for plants that are particularly suited to these growing conditions,” says Angie. “Try cacti and succulents, natives and Mediterranean plants like lavender, echium, olives and rosemary.” Hardwearing plants generally share similar features, such as hairy or waxy leaves, or silver-toned foliage.

Keep in mind 

• Check water restrictions with your local council. 
• Wear safety equipment (mask, gloves and eye protection) when applying soil wetter, compost and mulch products. Always follow the product’s instructions.
• Store products for improving soil out of the reach of children and pets.

Want to set up an irrigation system?

Watch our instructional video on how to install irrigation sprayers and drippers. 

Photo Credit: Getty Images and Natasha Dickins