The recent Oregon heat had us all flocking to the comfort of our homes, but unless our plants are in pots and can be brought indoors, they are stuck outside, bearing the heat wave without an escape. Most summers can be warm, but abnormally high temperatures can be stressful on plants, resulting in sunburn, wilting and even death.

Thankfully, there are methods that can be used to moderate these damaging effects of the rare Oregon heat. Here are our 5 ways to help your plants survive the summer heat and how to determine if you can revive a ‘fried’ plant.

Plants in containers are more vulnerable to extreme heat and weather because the air temperatures can ‘cook’ the roots as well as the tops of the plants. Shallow-rooted plants such as annuals, especially those in your hanging baskets, can be the most sensitive to the effects of a heat wave, while succulents can tolerate the heat well.

1. Give your plants extra water.

High temperatures will require more watering because there is an increase in the rate the water is lost from your plant’s leaves, resulting in sunburn damage and wilting. You will want to increase the amount of supplemental irrigation you give your plants. The best time to do this is the day before a heat wave arrives, so make sure you keep an eye out on the weather forecasts.

When you water your plants is also very important to keep in mind. Watering in the middle of the day will not be as effective because your shrubs, perennials and plants are devoting their energy to surviving the heat, not taking in water. The best time to water plants is in the morning when temperatures are lower.

Make sure to avoid over watering because this can also harm your plants, even in a heatwave.

2. Skip Fertilizing

Plants use all their resources to survive a heat wave and cannot spare the energy needed to take in fertilizer. Instead, the fertilizer remains in the soil and can burn the plant. When the hot weather is over, you can return to your regular fertilizing schedule.

3. Avoid pruning.

When you see the sunburned growth on your plants it can be tempting to prune it away but put away your pruners! This sunburned foliage is protecting the interior of your plant by providing shade and coverage from the sun. Wait to prune away this sun-damaged growth until the temperatures return to normal. To be extra safe, wait until the summer is almost over before you prune just in case there is another heat wave.

4. Provide Temporary Shade

On a hot day, we all keep an eye out for a shady spot to escape the heat, unfortunately, plants cannot move toward or into the shade, but we can bring the shade to them. Shade cloth and landscape burlap can be placed on top of the plants to protect them from the sun by screening out most of the sun that will hit them.

If you have container plants, it is beneficial to have them on rollers so that you can move them around as needed to put them into shady areas.

5. Mulch, mulch, mulch

Roots can also be affected by hot temperatures. Adding a layer of mulch around ground covers, shrubs and trees will keep the soil a couple of degrees color while stopping it from drying out.

Apply your mulch about 3 inches thick around the plants, spreading it near the drip line or water source and make sure to keep it about 6 inches away from tree trunks.

Dead or alive?

The effects of a heat wave can leave your plants ‘fried’, so how can you tell if it is dead or alive?

Wilting

When a plant is unable to take up water quickly enough to replace what it has lost is common with unusually hot weather. Each plant has its own “permanent wilting point” that determines if it can recover or not. If it goes past this point, there is no amount of water or care that can bring it back. If your plant’s leaves begin to plump up after you have watered it deeply, then the plant should be fine.

Sunburned leaves

When this happens, check to see if the stems are pliable or green; if they are, your plant is still alive. If there is any green present on the leaves, this also means your plant is salvageable. Like we mentioned above, avoid removing the sunburned leaves until the heat wave is over because they protect the healthy parts of your plant.

Replacing Plants

One of the hardest decisions we can make as gardeners is whether to keep a plant or annual that is on the decline. The best thing you can do, after you have determined the plant won’t survive, is to remove the plant and take it as an opportunity to give your garden a refresh. It saves you from having to constantly worry about the plant and whether it has survived the heat.

More Resources!

Looking to our Garden for a Lesson in Resiliency

How to Save Water While Keeping Your Plants Healthy

Vacation Watering Tips