10 Ways to Protect Garden Plants from Extreme Heat

Summers can become scorching no matter where one resides, and nothing surpasses the satisfaction of cooling down with a tall refreshing beverage while facing a robust fan. If you’ve been experiencing an exceptionally warm summer lately, you can relate to what you just read.

Regrettably, our beloved plants do not have the luxury of finding relief or taking a dip like we do when the temperature becomes unbearably hot, leaving them unable to do much except breathe…

But since you seem concerned about your plants, I sense that you’re here to discover ways to shield them from the heat. So, without further ado, let’s delve right into it, shall we?

Plant Seeds with Greater Depth

One of the initial steps you can take to ensure your plants survive the dreadful heat of summer is to plant your seeds slightly deeper right from the beginning.

This step holds particular significance if you inhabit an area prone to scorching temperatures throughout the year. The combination of warm weather and direct sunlight can swiftly parch the topsoil, leaving your poor plants helpless.

By planting your seeds an inch or two deeper than usual, you grant the root systems an opportunity to evade dehydration or suffocation if the topsoil becomes desiccated.

This primary measure serves as a proactive way to establish your garden on the right path and provide your plants with the best chance of healthy growth.

Prevent Sunburn

Sunburns are the nemesis of plant enthusiasts and gardeners everywhere. However, during extreme heat, they often become unavoidable unless preventative measures are taken. Sunburns can hinder plants like tomatoes, eggplants, and peppers from blooming as they should.

Typically, the leaves of your plants reveal the most prominent signs of sunburn. They will turn white, indicating the detrimental impact of the sun on the unfortunate plant. This typically occurs when temperatures reach the mid-90s Fahrenheit.

The best method to avert sunburns is by gradually acclimating your plants to sunlight, but not direct sunlight. This should be done before transplanting them into the garden.

Hence, if you intend to move a plant outside, ensure it is exposed to sunlight for a period beforehand. Just like us, plants need to build up some tolerance to the sun before prolonged exposure.

Do not worry about plants already present in the garden; they have already developed sufficient protection against the sun.

Provide Sufficient Shade for Your Plants

One of the most effective ways to shield your plants from extreme heat is quite simple and easily achievable: provide shade. Proper shading ensures your plants are safeguarded against the scorching sun rays while enabling the soil to retain moisture and remain cooler.

Shade also guards fruits and vegetables against sunburn. Have you ever witnessed peppers and tomatoes displaying white or yellow patches? These marks result from severe sunburn, which can lead to premature rotting of these crops.

Various shading options are available for your plants. You can opt for a simple solution like draping bed sheets over sticks or a more complex approach such as erecting a shade canopy.

As long as your plants receive adequate shade, you can choose the option that suits you best. However, remember that while effective shading blocks out the sun’s rays, it should still allow for proper airflow.

The ideal shading material permits a limited amount of sunlight to filter through while providing ample UV protection.

Establish a Consistent Watering Routine

Maintaining a consistent watering routine not only protects your plants from dehydration but also ensures their survival during scorching summer heat. Properly watered plants develop healthy and robust root systems, which is always beneficial.

Water your plants regularly throughout the growing season, providing them with long, slow watering that effectively saturates the soil. A consistent watering routine offers greater benefits to your plants than sporadic bouts of watering.

The soil in which your plants grow should remain adequately moist, encouraging root growth. Most plants can develop underground roots as deep as their height, but only when they receive appropriate moisture and nutrients.

When plants possess strong roots, they become more resilient and capable of withstanding intense summer heat.

So, what constitutes a good watering routine? While this may vary depending on the plant types you cultivate, ensure the soil remains moderately damp at all times. Avoid making the soil soggy, but never allow it to dry out completely either.

Consider watering your plants early in the morning, especially when a heatwave is on the horizon.

Natural phenomena like heatwaves can rapidly deplete moisture from shallow roots and dehydrate the soil. By watering early, you help ensure the soil and roots remain sufficiently hydrated and less affected.

Water Before Heatwaves Arrive

This may seem obvious, but it is crucial to stay informed about weather forecasts in your region. Knowing when a heatwave is imminent allows you to prepare your plants accordingly.

While watering your plants before a heatwave is advisable, be cautious not to overwater them and drown the poor plants.

Providing a generous, deep drink of water the night before or on the morning of an anticipated heatwave should suffice.

Avoid watering your plants throughout the day, even if they appear wilted. Instead, check the moisture level of the soil by inserting your finger an inch or two into it to assess its dryness.

Although your plants may appear droopy and limp during the day, they will recover once the sun sets.

However, if your plants are already drooping early in the morning, it is a clear sign that they are thirsty.

Avoid Wetting Plant Leaves

While it may appear delightful to witness water droplets cascading off plant leaves, it is best to avoid such situations during scorching weather conditions.

Remember how people can get severe sunburns during foggy weather or when water droplets cover their skin? The same principle applies to plant leaves.

Moisture acts as a magnifying glass, amplifying the sun’s intensity. Thus, it is unwise to have your plant leaves covered in water droplets, as they risk being scorched.

As much as possible, focus on watering the soil around the base of your plants, especially during heatwaves or extremely hot weather.

Harness the Power of Mulch

A gardener spreading mulch around young lettuce plants.

Plants can endure harsh conditions if their roots are protected and shielded from above-ground circumstances. Therefore, your plants can survive even severe heatwaves as long as their roots remain undisturbed.

Mulching plays a vital role in keeping your plants alive during summer and extreme heat. Mulch acts as a protective layer placed atop exposed soil.

This layer of material acts as a buffer against temperature fluctuations and helps maintain more stable soil temperatures. Additionally, mulch aids in reducing evaporation, preventing the soil from drying out.

Opt for organic mulch options, such as pine needles, wood chips, small bark, aged compost, shredded leaves, or straw. Spread the mulch around the soil near your plants to shield them from heat and retain moisture.

Maintain Overall Plant Health

A garden filled with healthy lettuce plants.

Although this advice may appear general, ensuring your plants’ overall health is key to their protection and survival during extreme heat.

Healthy and happy plants possess a better chance of enduring heatwaves and hot conditions, requiring less intervention from you. Stressed and malnourished plants may perish even with your best efforts to sustain them during such conditions.

Immediately eradicate any weeds as soon as they appear, ensure no pests are troubling your plants, and provide support to plants that require

staking. Furthermore, keep animals at a distance from your plants and enrich the soil with the necessary nutrients.

In addition, plants have their own immune systems, just like humans do. These immune systems help them cope with and recover from various environmental stresses, including diseases and pesticides.

In our garden, we strive to cultivate the strongest and most resilient plants possible by incorporating organic inputs such as compost tea, aged compost, aloe vera fertilizer made from fresh leaves, mycorrhizal, and worm castings. These elements nourish the soil food web, enhance nutrient utilization, and increase the plants’ resistance to pests, heat, and other stressors. Although minor ailments may still affect our plants occasionally, these measures greatly assist in their overall well-being.

Avoid Overwatering

Overwatering your plants can be as harmful as not watering them enough. Even if your plants appear extremely thirsty, it’s crucial to avoid excessive watering. Always assess the soil condition before providing water, ensuring you respond to the plant’s actual needs rather than assumptions.

Overwatering can lead to oxygen deprivation, which is vital for healthy growth. Additionally, it promotes fungal growth in the soil when there is excessive moisture.

Even during alarming temperature spikes, strive to adhere to your watering routine and only water your plants as necessary.

Prune at the Appropriate Time

A gardener carefully pruning tomato plants in the garden.

When facing heatwaves and extreme heat conditions, it is advisable to postpone any pruning activities. Even plants that appear healthy can experience stress during severe heat, and pruning them at such times can exacerbate the situation.

Allow your plants to grow naturally and postpone pruning until the weather cools down and becomes more favorable.

Please note that this rule may not apply to all flowers, but roses are particularly susceptible to diseases and should be handled differently.

Bonus Tip

Here’s a quick bonus tip to help your plants survive extreme heat: hold off on using fertilizers for now.

In high temperatures, plant root systems tend to suffer, and the additional absorption of fertilizers can potentially cause further damage. If you must use fertilizer, opt for organic options.

In general, organic fertilizers should be suitable, but avoid those containing blood, fish, or manure, as they may contain salts that contribute to heat stress.

When Is the Temperature Considered Extreme for Plants?

Determining when temperatures become extreme for plants varies depending on the plant species. Cold-season crops like cabbage, broccoli, bok choy, radishes, lettuce, and leafy greens prefer soil temperatures in the 50s and 60s degrees Fahrenheit. Once temperatures rise above 75 degrees Fahrenheit, these crops may begin to wilt or bolt.

Bolting occurs when a plant rapidly develops a flowering spike and sets seed, ultimately leading to its demise. Such crops may not survive if temperatures reach 90°F. To prevent cool-season crops from bolting, it is essential to understand how to manage them in high temperatures.

Summer vegetables like beans, peppers, and tomatoes thrive within a temperature range of 75° to 90°F. However, even heat-tolerant plants can experience irritation, decreased productivity, or damage when temperatures exceed a certain threshold.

Tomatoes, for example, are more susceptible to blossom drop and fruit development issues when daytime temperatures consistently exceed 95°F. Squash and zucchini plants’ growth can also be affected by temperatures surpassing 85 degrees Fahrenheit.

When dealing with heat, young plants are more vulnerable than mature ones, regardless of the plant variety. Pay close attention to seedlings due to their delicate nature and shallow root systems. During heatwaves, it might be advisable to keep containerized seedlings indoors or in a shaded area away from direct sunlight. Avoid transplanting new plants outdoors during a heatwave.

Quick Solutions vs. Long-term Planning for Heatwaves

During short-lived heatwaves, some plants may encounter challenges related to pollination and production, but these issues are usually temporary. Plants tend to slow down their growth, much like we do when it’s too hot to move comfortably.

In such cases, follow the provided advice to safeguard your garden, as the plants will recover once the temperature cools down and returns to normal.

However, in regions where prolonged high temperatures are anticipated, adopting long-term strategies becomes crucial for combating the heat. For instance, residents of places like Nevada or the Southern United States may choose to avoid growing squash and tomatoes during the hottest months and instead opt for spring and fall planting.

For a more sustainable approach, selecting hardier plant species, using raised beds instead of containers (which are prone to drying out and temperature fluctuations), or constructing long-lasting shade structures can be beneficial.

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