During the heat of summer, the sun may not be so forgiving on your garden. Sydney-based horticulturist Helen Young shares some simple strategies to protect your plants from dehydration and sunburn.
1. Keep soil moist
If you’re anticipating very hot temperatures during the day, watering your plants early in the morning will maintain moisture in the soil and avoid plant stress.
“Plants that are dry on a very hot day will wilt and the leaves will burn much more easily than if they’ve got plenty of water around the roots,” says Young.
To cut down on the need for additional watering, use a soil wetting agent in your garden. “It’s a product that you can buy and put a couple of capfuls in the watering can. It’ll last for six months, and helps the water penetrate and hold.”
Wetting agents increase water absorption of the soil and improve water retention by dispersing water evenly into dry soils that repel water.
You can use decorative pebbles as a garden mulch
Mulching around roots can keep plants cooler, conserve water, and help retain moisture. Adding a good layer of mulch over the top of your soil creates a barrier from the sun and reduces evaporation from the soil surface. “You can have a woody mulch, like pine bark, or you could have a soft mulch, like sugar cane mulch. They all do a similar job.”
“Even in a Mediterranean garden, you might use stone or pebble and that’s still a mulch. It’s still putting a covering over bare soil that traps the moisture,” Young adds.
To prevent excess water loss, an anti-transpirant plant protector can be applied to reduce the damage of the sun against wilting, burn, heat stress, and drying winds.
“You know, it’s a bit like us: you want to cover up and you want to have sun protectant. There is a thing that people can use that’s a bit like sunscreen called an anti-transpirant. Yates makes a product called ‘DroughtShield’. You can spray it on the leaves of plants and it’s like a polymer coating that helps stop the leaves losing so much water, so it helps plants survive heat.”
4. Potted plant care
When it comes to your potted plants, extreme heat can dry them out really quickly, especially those in small or dark coloured pots. “The temperature of the roots in a pot can be way above the air temperature, so do everything you can,” says Young. She suggests moving them into the shade and grouping them together for added cover.
A simple and cheap solution for physically protecting your plants during the heat of the day is to lay a piece of shade cloth over them to prevent sunburn. It could be an old tablecloth, sheet, or tea towel — you can even prop open a beach umbrella in your garden!
“I do it to all my plants,” says Young. “I’ve got a beautiful Japanese maple and when I know it’s going to be 44°C, I water it in the morning and cover it with an old bedsheet. I use clothes pegs to peg the sheet on so it doesn’t blow off in the wind, and then I just take it off at the end of the day.”
And for those looking for a gardening project, why not plant a tree? “There’s some terrific statistics on how much power you can save on air conditioning if you have a well-placed tree that shades windows or the roof of your house,” she explains.
“Underneath a big, shady tree you’ll always be ten degrees — or more — cooler than it is out in the open sun so summer days are a great reminder to us to plant a tree.”
What kind of plants do you have in your home and garden?