How Do You Keep Plants Cool in Heat Waves?

“The summer has been hotter than it’s ever. How can I protect my plants from the severe heat?” Angie of Atlanta, Georgia

Answer: Georgia summers are notoriously hot. Being faced with temperatures well over 95 degrees F for days on end is a trial. Here are some ways to help protect your plants, especially those that are less heat tolerant. Specimens planted in full sunlight during the hottest times of the day (around 2:00 pm to 4:00 pm) need the most protection.

Four Ways to Cool Plants in High Heat

  1. Irrigate plants very well in the early morning. If temperatures exceed 100 degrees F, water again in the evening after the sun has fallen.
  2. Protect plants that are in full sunlight with floating row covers fitted with white shade cloth. These covers are easily placed over plants and removed. You can also simply purchase shade cloth and drape it over highly exposed plants. Both methods help. Gardeners in your area have also informed me that they have been moving patio umbrellas around their yards to shade their most prized plants. (One even said that her neighbor did not, and it resulted in some substantially fried rhododendrons and hostas.)
  3. Move containers into shaded areas or indoors during the most dangerous heat and water twice daily.
  4. Opt for lightweight, light-colored mulches. A cooling layer of straw around vegetable roots will protect plants from heat, and long-fibered sphagnum peat moss makes a good, cooling cover for shade beds and containers. (Click here to learn about more mulch options.)

I also want to note that pets and wildlife also feel the stress. Leave water out for the animals and keep your pets from going outdoors for extended periods and walking on hot surfaces (grass only!). I also recommend that you read the following two garden articles for more helpful tips.

Cool Gardens: Designing for Summer Temperature Control

Nine Water-Saving Garden Tips to Fight Drought

Stay cool and happy gardening,

Jessie Keith

Grower’s Gold Horticulturist

How Do You Save Heirloom Pepper Seeds?

“I would love advice on saving seeds off of heirloom bell peppers.” Question from Amy of Lewiston, Idaho

Dear Any,

I have good news! Peppers are some of the easiest seeds to save because peppers are dry, rather than fleshy, fruits with open interiors. The seeds are easy to gather from the ripe fruits.

What is important is waiting until the fruits are ripe to harvest the seeds. Green peppers have immature seeds that will not germinate, so wait until the peppers have developed full color. Once the fruits are fully colored and ripe, the seeds will be ripe.

Collect the seeds, place them in a labeled packet, and store them in a cool dry place through winter. I generally start my peppers in late winter or spring, at least 8 weeks before the last frost date.

Please watch the video below for tips about how to grow peppers organically!

Happy gardening,

Jessie Keith

Grower’s Gold Horticulturist


Why Are My Tomato Leaves Curling?


Upward curling tomato leaves indicate stress more often than disease.

“My tomato plants have leaves curling upwards along the edges. Why?” Questions from Andy of Zionsville, Indiana

Answer: Based on your photo, your leaf curl appears to be caused by something in the environment rather than a disease. There is a Tomato Yellow Leaf Curl Virus, but your plant does not appear to have several of the symptoms, such as stunting, yellowing, and leaf browning. Tomato plants, like yours, more commonly experience physiological leaf curl when subjected to various environmental stresses. Here are four possible sources of stress able to cause leaf curl.

Environmental Tomato Leaf Curl Causes

  1. Water stress (too little or too much water) — Vines fail to grow as well when water is lacking, and they develop root rot when there is too much water. Either problem can cause leaf curl. Provode plants with regular, even watering for best growth.
  2. Heat stress — Temperatures over 85 degrees F can cause some tomato plants stress, resulting in leaf curl. Some tomatoes are more heat-tolerant. Two good heat-tolerant varieties are the large, red-fruited ‘Heatmaster‘, which can take the high heat of the South, and disease and heat-resistant ‘Heatwave II‘, which bears deep red tomatoes with good flavor.
  3. Wind stress — High winds can cause rapid water loss from the leaves. Leaf curl can result.
  4. Herbicide damage – Glyphosate herbicide damage is most common and can cause leaf curl if a small amount reaches your tomatoes from a upwind application.

Could any possibilities be the cause? Please let me know. In the interim, click here to read more about leaf curl, and watch the video below about growing flawless tomatoes!

Happy gardening!

Jessie Keith

Grower’s Gold Horticulturist