Hot Weather Gardening Part 5: More Tips to Help Plants Beat the Heat

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Hot Weather Gardening Part 5: More Tips to Help Plants Beat the Heat

With a bit of extra attention you can prepare your plants for heat and help them to stay healthy during heatwaves. Here are more tips to help plants beat the heat. Know what gardening tasks for heatwaves are important to protect your plants and what tasks can harm them.

This is the 5th in a series of articles with my precautions, tips, advice, and ideas for gardening in Southern California’s high heat from midsummer through fall. See below for links to other articles in the series.

Hot weather and high temperatures can be dangerous. Basic safety precautions are important including sun protection, hydration, working mornings or evenings when temperatures are cooler, avoiding exertion and working for short periods only, and having indoor cooling environments available.

Home gardening is one of the safest and most-rewarding activities during the COVID-19 pandemic. For other helpful articles, see our blog page Dig In.

More Gardening Tasks for Heatwaves

• Ensure that plants and gardens are well mulched, that you are providing temporary shade to heat-sensitive and stressed plants, and that automated irrigation and sprinklers and are watering effectively. When monitoring your yard, do so early in the day before the extreme heat and take precautions to protect your own safety. See Help Your Plants Survive Heatwaves and other previous articles in this series.
• Harvest ripe and almost-ripe vegetables and keep plants harvested during heatwaves. Many vegetable crops, including warm-season crops, lose quality during hot weather by becoming tough or bitter. In many cases, harvesting early for baby vegetables such as with cucumbers and zucchini is better than no harvest during hot weather. Harvesting regularly and as completely as possible will provide extra yield for you and reduce stress to plants.
• Remove buds, blooms, and spent blooms from plants to reduce stress. Plants generally put priority on producing fruit and seeds even if this means exhausting their resources and pushing themselves to the limit of survival. It’s usually not practical to remove blooms from every plant in your landscape, but if you have stressed plants that you care about, it may be worth the time to clip off young flower buds and blooms.
• Remove leaves from plants that can’t be prevented from wilting. In some cases, plants that aren’t adapted to heat may be unable to draw in enough water from to prevent wilting, even when there is sufficient water in soil. Most healthy plants can lose leaves repeatedly and still recover. Under most circumstances, wilting and repeated wilting are a greater threat to plant survival than losing leaves.
• Do a thorough pass to remove weeds, which compete with desirable plants for water and nutrients. Some weeds also support pest insect populations and allow for vectoring diseases to desirable plants and trees. Remove weeds from under shrubs and trees, and apply mulch to minimize regrowth.
• Remove dead, diseased, and infested plants. Prune out diseased stems and leaves that are severely affected by mildew, rust, and other foliar diseases to minimize infection of healthy plants. Most plants and trees are stressed to some degree during high heat, and are therefore less able to fight off pest and disease infestations during this time.
• Move heat-sensitive plants in containers away from hot, harsh southern and western exposures to shaded or partly shaded areas. Consider incorporating more container gardening into your plan for spring/summer gardening next year to make it easier to protect plants and extend harvest during hot weather.
• Plan for excluding or discouraging bird and mammal pests, which are often most active in California gardens and urban landscapes from late summer through fall; these animals are often active after long periods without rain and when less food is available in wild areas.
• Have the gardening bug but don’t want to go outdoors during hot weather? There’s plenty that you can do indoors to prepare for the fall gardening season in mild-winter California areas, such as planning your garden, ordering seeds and supplies, and starting seeds indoors, particularly for vegetables that take a long time to germinate or establish such as tomatoes and parsley.

What Not to Do For Plants During Heatwaves

• Minimize or discontinue fertilizing. During high heat, most plants reduce growth or stop growing entirely, and even if they appear healthy and don’t wilt, they may essentially be trying to survive until temperatures cool. Fertilizers and amendments, especially those containing nitrogen such as manures and composted manures, encourage or force plants to grow, which can be harmful and contribute to stress, disease, and death of plants during hot weather. There are exceptions, but generally unless you have a specific and important reason for fertilizing, or are sufficiently expert to make decisions about fertilization, it’s best to avoid doing so during hot weather or from early summer until temperatures cool again in fall.
• Minimize use of lawns as much as possible. Have you ever noticed that lawn areas where people or pets walk regularly tend to die during hot weather? If you want to keep your lawn healthy during heatwaves, take the time to detour around your grass.
• When possible, prevent pets and animals from doing business on your lawn or garden during periods of high heat. While animal urine is naturally beneficial in most soils when plants are actively growing and during cool-to-warm weather, it’s too much for lawns. Combining heat with the salts and nitrogen in animal urine is guaranteed to leave dead areas in the lawn and may harm or kill other plants during heatwaves.
• Avoid overhead watering of plants and trees such as with spray irrigation or hand watering. Leaf mildews, foliar diseases, other plant diseases, and infestations from insects such as whiteflies may become rampant during hot weather. Wetting leaves frequently during hot weather tends to foster diseased leaves. Water plants from above once every few weeks or occasionally rinse leaves with a hose to remove dust and pollutants to maintain optimal photosynthesis.
• Avoid watering drought-tolerant native plants. Many California natives in landscapes naturally go dormant and may appear dead during summer and other stressful periods. Many California natives are typically quiet during summer and their immune systems may be less active; too much water, or for some species more than minimal extra water, may kill them.

More Tips and Gear to Beat the Heat

• The next article in this series, “Hot Weather Gardening Part 6: More Tips and Gear to Beat the Heat” will discuss more tips for hot-weather gardening from low-tech solutions for cooling your body while outdoors to tips to avoid overheating your cell phone while gardening during heat.

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Articles of interest for gardening during heat include:

Hot Weather Gardening Part 1: Bikram Gardening

Hot Weather Gardening Part 2: Mindset and Acclimation

Hot Weather Gardening Part 3: Tips and Gear to Beat the Heat 

Hot Weather Gardening Part 4: Help Your Plants Survive Heatwaves

Hot Weather Gardening Part 6: How to Cool Your Body and Your Gear

GardenZeus Tips for Providing Shade During Hot Weather

GardenZeus recommends Botanical Interests as an excellent source of quality seed. Order now for planting in the fall after the weather cools.