As summer comes to a close, the burning question among gardeners is what to do about all the heat-damaged foliage on garden plants. Burnt leaves and fronds in the garden look awful and are a constant reminder of the hot weather we’ve been experiencing.
Ugly as it is, the best thing to do about burnt growth is to leave it be and to provide as much water as possible to damaged plants. Regular deep watering along with a weekly application of a seaweed tonic (not one containing any fertiliser) helps plants to recover.
Our natural instinct is to prune away the heat-damaged foliage, but sometimes it’s not always the best action to take.
If the weather forecast in your area continues to be for warm to hot and dry conditions with low humidity, there could be more heatwaves ahead and plants could sustain more damage.
The damaged growth is offering some protection to the foliage beneath.
Damage from heat is likely as temperatures climb above 35C and particularly if accompanied by hot winds and low humidity.
Remember, too, plants can be burnt by reflected heat from nearby hard surfaces including paving, fences and walls.
Should you prune heat-damaged leaves?
Sometimes it’s best to wait. The reason to wait before cutting plants back is that pruning stimulates new growth from lower down on the stem.
Fresh new growth is soft and quite likely to be burnt or even killed by high temperatures and a lack of water.
Even without cutting plants back new growth will occur as plants struggle to recover.
Over the next few weeks burnt leaves on trees and shrubs will be discarded. It will look as if autumn has come early.
Plants that are completely dead, which may include shrubs, annuals and vegetables can be removed entirely.
Cover the bare area that is left by removing a plant with a layer of organic mulch. Replanting can occur in autumn when temperatures will be cooler and the days shorter.
When to prune heat-damaged foliage
Once it looks as if there has been a change in the weather with either a sustained cooler period or even better, rain, prune damaged growth.
As you prune, cut to just above a node, the point on a stem from where new growth will occur.
Clumping plants that grow from a rhizome, crown or thickened root system in the ground can be cut back hard. New growth will appear from the base of the plant.
How to protect plants from sun damage
Whether you prune now or later, it is vital to protect plants from future heat damage.
Cover plants, especially those with new growth, using outdoor shade solutions including shadecloth, towels, sheets or even beach umbrellas provided there’s no wind to dislodge them.
If the plant is being damaged by reflective heat, lay or hang cardboard, blinds or shadecloth across the surface that’s reflecting the heat.
If plants have produced new growth that can be damaged, it can be protected with an anti-transpirant spray such as Droughtshield. These products also protect plants from frost damage.
FOR MORE TIPS ON CREATING A HEAT-TOLERANT GARDEN TRY:
How to save your garden from the scorching hot sun
How to help your garden survive a drought
15 expert summer gardening tips
Essentials for protecting plants from heat damage
Yates Drought Shield, $29.99, Ebay
Save water and protect your plants at the same time by applying Yates’ Drought Shield. The product leaves a protective film over the leaves which guards against heat, water loss, drying winds and droughts.
Sun shade cloth in beige, $27.95 (1.83 x 10m), Amazon
Creating a physical barrier between vulnerable plants and the sun is another great, chemical-free way to protect plants from heat damage. This shade cloth blocks out 50% of the sun’s rays and is resistant to tears and fraying.
Vegtrug 1m small frame and shade cover, $89.50, Amazon
Keep your leafy greens looking fresh with this raised garden bed shade cover and frame. It’s also great for raising seedlings and protecting cool season crops. The cover cuts up to 50% of the suns rays.
WriterJennifer Stackhouse
