Whether your area is experiencing a whole year or just a temporary heat wave, your plants can be damaged by exceptionally hot sun. The result of this sunburn or sunscald will appear as crispy brown patches on most foliage or flower petals. It can also discolor some fruits and vegetables in a way that my not look burnt at all.

First and foremost, just like frost damage, you often won’t notice the damage right away. Sometimes it takes a week or two before you walk into your garden and discover the shocking burns. By then you might have forgotten the extreme weather of a couple of weeks ago and wonder what awful thing took place in your garden or what you did wrong. Remind yourself that weather injuries may take some time to appear.

In most cases sunscald or sunburn is likely to be superficial. If you look at this sad picture of a totally sun-fried tomato plant, you may be surprised to learn that the sun-bleached white tomatoes will have perfectly tasty and normal-looking red interiors. The tomatoes were only cooked on the outside skins. In this case, the whole plant was burnt so badly it succumbed.

But woody plants like this lilac are likely to shed the damaged leaves and grow back healthy ones.

Lilac leaves show sunscald damage.

 In the case of this poor young avocado, all the leaves were all crisped from hot sun and lost, but you can see the healthy framework remains and new growth is already starting.

This young avocado tree has shed its scalded leaves but the plant itself remains green and healthy. It will grow back.

If you move a plant from a shady spot suddenly into the sun you won’t need a weather heat wave to show you what sunscald looks like. Indoor plants or plants used to outdoor shady locations should be introduced to (even the smallest bit of direct) sun slowly. The leaves need to acclimate to the increased exposure a little at a time. Just as you will be sunburned when you expose sensitive, unaccustomed skin to bright sun, so, too, will your plants.

Severe sunscald can kill a plant. The smaller the plant and the softer the tissue, the more damage is likely to be done. Before giving up on your sunburnt plant, give it sufficient water and added shade and be patient. There’s a good chance lightly affected or tougher plants will drop their burnt leaves and grow out new, healthy ones in their place.