Purple Pillar Hibiscus in summer heat

Tips & Techniques for Gardening in Extreme Heat

Gardening can be a delightful experience, but when heatwaves strike, it can become quite challenging to continue gardening in extreme heat. I find myself less motivated to go out and water plants or check for pests when the heat & humidity become unbearable for more than a few minutes at a time. But high temperatures and scorching sun also affects plants. Heat can quickly stress plants and lead to potential garden disasters, and high humidity can promote the rapid spread of garden diseases. However, with careful planning and a few smart strategies, you can continue to nurture your garden through the hottest days and ensure its survival and success. In this blog post, we’ll explore tips and techniques to help ensure your gardening skills adapt to remain resilient even in the midst of extreme heat.

Be Proactive: Plan for Possible Extreme Heat

Choose Heat-Tolerant Plants: If your area is prone to high heat and humidity, prioritize choosing heat-tolerant varieties that can withstand high temperatures and prolonged sun exposure. Native plants and drought-resistant species are often excellent choices for extreme heat gardening. Read plant tags and descriptions to identify plant varieties that may be more disease resistant and tolerate pressures brought on by high humidity.

For Zone 7b, some of my favorite heat-tolerant plants include lantana, perennial hibiscus, lorapetalum, annual vinca, and butterfly bush.

Plant in the Right Spot: Position your garden beds strategically to take advantage of partial shade during the hottest part of the day. Shelter sensitive plants near walls or under taller vegetation to provide some respite from the sun. Even if your yard has no natural shade during the day, that’s ok — you can later add artificial shade by using shade cloths.

Install an irrigation system: When it’s hot and humid outside with excessive heat warnings, you don’t want to be outside for half an hour watering plants. Install a simple irrigation system to help automate waterings and reduce your exposure to the heat and humidity. Utilize drip irrigation or soaker hoses to deliver water directly to the plant’s root zone, minimizing water loss through evaporation.

Drip irrigation in our raised bed vegetable garden

Mulch: Add Nature’s Protective Blanket

Apply Organic Mulch: Spread a layer of organic mulch, such as straw, wood chips, or dried leaves, around the base of your plants. Mulch acts as a protective barrier, keeping the soil cooler and retaining moisture. Make sure the mulch layer is thick enough (at least a couple of inches) to help protect plant roots from the heat and preserve moisture in the ground.

Use Reflective Mulch: In areas with intense heat, consider using reflective mulch to bounce sunlight away from the soil surface and reduce soil temperature. You can purchase reflective mulch in different colors, like red (I’ve often seen red mulch associated with tomato plantings) and white (to help reduce heat absorption and keep soil cool).

Follow Proper Watering Techniques

Establish a watering schedule. Establish a regular watering schedule, aiming to water early in the morning or late in the evening when temperatures are lower and more tolerable. Avoid watering during the day, which might promote more evaporation of the water. In addition, avoid spraying or splashing water on plant foliage during the day to avoid burning or scolding the plant leaves.

Water Deeply and Infrequently: Instead of frequent shallow watering, water deeply to encourage plants to develop strong root systems that can access moisture stored deeper in the soil.

Use Watering Timers: Use automated watering timers to ensure plants receive consistent moisture even if you’re away or unable to water manually. I use a simple dial-type timer, where I can turn on the faucet, set the timer to 30 minutes, then go back indoors.

Incorporate Shade Cloth and Protective Covers

Shade Cloth: Install shade cloth over vulnerable plants to reduce sun exposure during extreme heatwaves. Shade cloth can be easily removed or adjusted based on weather conditions. Garden shade cloth, also known as shade netting or sun shade fabric, is a versatile material made from a lightweight, woven, or knitted fabric that comes in various densities or shading percentages, such as 30%, 50%, or 70%. Garden shade cloth is available in different sizes, often sold in rolls or cut to fit specific garden structures like hoop houses, pergolas, or trellises. Shade cloth is easily installed and secured using clips, ties, or ropes.

Row Covers: Employ row covers to shield young seedlings or delicate plants from direct sunlight. Row covers also offer protection against pests and can help maintain consistent moisture levels. These covers are typically made from breathable, translucent fabrics like spun-bonded polypropylene or floating row cover fabric. In addition, row covers create a microclimate around plants, keeping them slightly warmer during cooler temperatures and providing a bit of shade during scorching heat, which can help extend the growing season.

Be an Early Riser: Garden in the Morning

Early Gardening Sessions: Schedule gardening tasks during the cooler parts of the day, typically early morning (though around here, the mornings can still be quite humid). This not only helps you avoid the worst of the heat but also allows plants to absorb water efficiently before the sun’s intensity peaks.

Stay Vigilant & Be an Agile Gardener

Regular Plant Inspection: Regularly inspect your plants for signs of heat stress, such as wilting or yellowing leaves. Address any issues promptly to prevent further damage. Be careful to avoid overwatering plants, which can also make plants wilt. Stick your finger into the top few inches of soil near plants to more accurately determine moisture levels in the soil.

Flexibility in Planting: Be prepared to adjust your planting schedule based on weather forecasts. Delay planting if extreme heat is expected, and prioritize the protection of existing plants. For example, I sometimes have to delay planting my fall vegetable garden because of heatwaves in late July and early August. Similarly, if I’m starting vegetables from seed directly in the garden, I may wait until an overcast day or period of several rainy days to help keep the seeds moist for germination.

Summary

Gardening during heatwaves requires careful planning, thoughtful techniques, and a touch of flexibility. By choosing heat-tolerant plants, implementing proper watering strategies, and using protective measures like mulch and shade cloth, you can navigate extreme heat with more confidence. Remember to stay vigilant, observe your garden closely, and adjust your practices accordingly. With a little preparation and care, your garden will not only survive but thrive during even the most intense heatwaves, proving that your green thumb is resilient and adaptable even in the harshest of conditions.

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