Intense Summer heat is becoming a regular challenge in the Pacific Northwest, making it essential to prepare your garden for both heat waves and drought.
From adopting smart watering strategies, providing protection, and recognizing early signs of stress, to helping plants bounce back after extreme conditions, a little preparation and care can make all the difference. Whether you’re gearing up for scorching days ahead or helping your garden recover, these tips will keep your plants healthy and thriving all season long.
How to Prepare Your Garden for a Heatwave
When a heatwave is on the horizon, a few simple steps—like smart watering, adding mulch, and creating shade—can go a long way in protecting your plants from heat and drought stress.
1. Adjust Your Watering Routine
- Water plants early morning or late evening to avoid water loss from evaporation.
- Water the soil around the plant at the root zone, not the leaves.
- Go low and slow—deep watering, delivered gently over a longer period of time, is far more effective than dumping a large volume all at once, which often just runs off the soil.
- Need a refresher on watering best practices? Find more helpful tips in our Watering 101 blog!
2. Provide Protection for Plants
- Apply mulch to bare soil and around plants with 2–3 inches of organic compost to retain moisture, reduce evaporation, and nourish the soil—keep mulch away from the base of plants.
- Shield tender plants from harsh sun with shade cloth, garden fabric, or even a well-placed umbrella—and, if needed, temporarily move them to a shadier spot.
Pay special attention to new plantings—they have smaller root systems, making them more vulnerable to heat and drought, so give them top priority for water and shade.
Identifying Signs of Heat Stress & Watering Issues
Even with the best preparation, extreme heat and drought can still take a toll on your garden. Knowing how to spot the early signs of heat stress and watering problems is key to stepping in before lasting damage occurs. Here’s what to watch for so you can take quick, effective action.
Foliage Symptoms
- Wilting leaves: Not always a sign of dryness—some plants wilt midday in extreme heat and recover once the sun eases; avoid overwatering in response. Persistent seasonal wilting may mean the plant needs relocation to reduce long-term stress. Continued wilt even in moist soil can be a sign of overwatering and potential root-rot.
- Sunburn: Red or prematurely colored leaves, brown edges, or shriveled foliage.
- Tip burn: Young leaves and new growth may wilt or burn when roots can’t take up water due to dry soil, root-bound conditions, or poor drainage leading to root rot.
- Light green or yellowing leaves: This loss of color suggests overwatering and possible root rot.
- Small leaves (and flowers): A sign of long-term drought stress.
Flower & Fruit Symptoms
- Flower loss: Perennials, annuals, and vegetables (cucumbers and squash) may drop flowers or fail to set fruit in high heat if not adequately watered during development.
- Poor fruit yield: Small, few, or bland fruits can result from inadequate or inconsistent watering during fruiting.
- Bitter flavor: Lettuce and other tender greens can turn bitter when repeatedly exposed to heat and dryness.
- Blossom-end rot (tomatoes): Dark patches on fruit bottoms often caused by inconsistent watering or allowing soil to dry out too much between waterings.
How to Help Your Garden Recover After Heat Stress
After a heatwave, take time to carefully assess your plants’ condition and create a thoughtful recovery plan. Remember, some plants might benefit from being transplanted to a cooler, more sheltered spot this fall to thrive long-term.
1. Don’t Overwater!
Overwatering can be just as harmful as heat itself, often leading to root rot. Newly planted or drought-stressed plants have shallow, limited root systems that can only absorb and store so much water at once. If the soil stays constantly wet, roots can suffocate, decay, and ultimately collapse—a condition that’s often fatal.
2. Gently Fertilize
Plants are often depleted of essential nutrients after extreme heat. Fertilizing helps replenish what’s been lost, supporting new root and leaf growth, boosting resilience, and aiding overall recovery. However, avoid heavy feeding that encourages vulnerable new growth—opt instead for a diluted, slow-release fertilizer such as E.B. Stone Organics All Purpose Plant Food to gently support recovery. And always be sure to water first, then fertilize—never fertilize a dry plant!
- Apply Kelp Meal or Fish Emulsion as a soil amendment, a top dressing, or mixed into compost tea to supply potassium and trace minerals that boost resilience and help many types of plants recover from stress without triggering excessive new growth.
- Feed veggies with organic, slow-release fertilizer like G&B Tomato, Vegetable & Herb Fertilizer.
- Fertilize container plantings and hanging baskets to replace nutrients that were flushed out by frequent watering.
3. Deadhead & Prune Lightly
Deadheading and light pruning can help plants recover faster and look tidier after heat stress.
- Remove spent blooms—cut off fried or faded flowers to encourage new blooms.
- Trim damaged leaves to spur a new flush of healthy growth—fully brown leaves from sunburn or drought stress can be removed; otherwise, they’ll drop naturally over time.
- Preserve green growth—if stems are still green, dormant buds may sprout, so only cut back brown, dead wood and avoid trimming into healthy green growth.
- Hold off on heavy pruning during hot summer months—removing too much top foliage can expose the tender inner layers to intense sun, increasing the risk of further burn.
- Be especially patient with slow-growing plants like Camellias and Rhododendrons, which can take several years to fully recover from severe sun damage.
4. Watch for Pests
Heat-stressed plants are far more vulnerable to pests and diseases. Prolonged high temperatures weaken their defenses, giving opportunistic insects an easy opening. Many pests hide on the undersides of leaves or blend in with foliage, making them easy to miss.
- Spider mites often appear during or after hot weather. Watch for yellowing or browning leaves and fine, silky webbing.
- Scale insects are common in sheltered spots—such as against a house or under eaves—especially on broadleaf evergreens and conifers. Look for shiny, sticky residue on leaves or a black, sooty mildew coating.
If you suspect an infestation, bring a plant sample in a sealed bag to our experts for identification and treatment options.
For more tips, check out our 20 Q&As for Extreme Heat Recovery blog, where we answer common customer questions. And if your plants need a little extra care, stop by one of our Garden Centers—our experts are ready to help you navigate heat and drought stress so your garden can thrive again.