The 3 Common Gardening Mistakes That Can Kill Plants During a Heatwave (And You Probably Don’t Even Realize)

Confession time: I have spent the past week desperately trying to keep both myself and my garden alive, and my efforts have made me realize that heatwaves have a funny way of making us panic. .. often in a way that does more harm than good.

During periods of extreme heat, plants go into survival mode. Instead of focusing on producing new growth, they’re conserving water and protecting themselves from stress. That means the way you care for your garden during a heatwave should look a little different than it does the rest of the summer.

I get it, obviously; the moment temperatures climb, it’s tempting to reach for the hose, trim away anything that looks dead, and give struggling plants a dose of fertilizer in the hope of helping them bounce back. All of those well-intentioned efforts, though, can and will make matters worse.

Gardening Mistakes That Can Kill Plants During a Heatwave

When temperatures soared recently, I set to work, And, when my husband (a professional gardener) got home, I proudly told him all of the wonderful things I had done to keep our plants alive and thriving in the heat.

Cue him lovingly, albeit very wearily, branding me a menace. Because, as it turns out, I had committed three cardinal sins when it comes to gardening in a heatwave…

1. Watering Incorrectly

When your plants start looking droopy in the afternoon sun, it’s only natural to want to grab the hose immediately. But watering in the middle of the day really isn’t the most effective approach.

In the heat of the afternoon, more water is lost to evaporation before it has a chance to soak into the soil and reach plant roots. Instead, the best time to water plants is early in the morning, when temperatures are cooler and plants have time to absorb moisture before the day’s heat sets in.

Rather than watering little and often, give plants a deep soak that encourages roots to grow further into the soil, where moisture lasts longer. Water at the base of the plant instead of wetting the foliage, and remember that containers and hanging baskets may still need an additional watering later in the day during prolonged heat.

Shop Garden Watering Essentials:

2. Fertilizing Stressed Plants

It’s easy to assume that a struggling plant needs feeding, but in very hot weather, fertilizer can actually add to its stress. In fact, many experts say that this is one of those common garden mistakes that can kill plants during a heatwave.

When temperatures are extremely high, plants naturally slow their growth to conserve energy. Fertilizer encourages fresh, tender growth, which requires even more water and is particularly vulnerable to scorching in hot weather. Applying fertilizer to dry soil can also increase the risk of root burn.

If your plants are looking stressed by the heat, focus on keeping them properly watered instead. Once temperatures return to normal and plants begin actively growing again, you can resume your regular feeding schedule.

3. Pruning away scorched leaves

I have a habit of picking at things (woe betide any split ends that appear in my hair; they will never be able to survive my obsessive snapping fingers). Still, while brown, crispy leaves aren’t exactly attractive, we should resist the urge to prune them off straight away.

Although damaged foliage may no longer look healthy, it can still provide valuable shade for stems, fruit, and developing leaves underneath. Removing any plant sunburn during a heatwave can actually expose the rest of the plant to even more intense sunlight, increasing the risk of sunscald and further stress.

Unless a branch is dead, diseased, or creating a safety hazard, it’s usually best to wait until cooler weather arrives before doing any significant pruning. Once the heatwave has passed, you can remove damaged growth and allow fresh new shoots to take over.

Try Slow Watering During Heatwaves:

Instead of trying to fix heat-stressed plants, focus on reducing the stress they’re under. My husband swears by a thick layer of mulch can help keep soil cooler and reduce moisture loss, and delaying planting or transplanting until temperatures drop is the best way to give new plants a much better chance of establishing successfully.

Basically, heatwaves can be tough on gardens, but they don’t have to spell disaster. Sometimes the best thing you can do is resist the urge to overcare for your plants. Be more chill. Do less!

Honestly, if you water wisely, avoid unnecessary pruning and fertilizing, and let your garden ride out the heat, your plants will often recover far better than you might expect once things cool down. Probably better than you if you forget that all-important suncream!