After a rainy and cool spring, starting June 11 the Eureka Springs area saw temperatures climb into the 90s with heat advisories being issued by the National Weather Service because the high temperatures, clear skies and humidity from wet soils pushed the heat index to more than 100°.
Gerri Hamby, owner of Planters Paradise, has some advice for people to help their plants survive this current heat wave.
“First of all, make sure that your plants are adequately watered, preferably in the evening,” Hamby said. “But if your plants are wilted, water them any time of the day. This will help them survive. For trees and shrubs, mulch is exceptionally helpful to retain moisture in the area where they are planted. Evergreens like spruce or yews also love to have water floated over their foliage.”
Excessive rain earlier wasn’t that great for plants not in well-drained soils. Hamby said excessive moisture brings out mold, fungus and slugs. And she warns that in excessive heat, too much water is as bad as not enough.
“The balancing act is that trees, shrubs and other plants that are well established are pretty dang resilient,” Hamby said. “Two things that will kill plants is it being way too wet or way too dry. That is where Mother Nature takes over. If something stays way too wet for a month, don’t feel bad if it dies; it is really not your fault and there is not much you can do about it. Other than that, plants are much more resilient than humans and they can survive and thrive in excessive heat. If you have ever been down an asphalt road that is closed, you will see trees coming up in the cracks. It is amazing how resilient trees and shrubs really are.”
White shade cloths can extend harvesting for cool season crops like lettuce, kale, Swiss chard, peas and snow peas. In excessive heat, the same shade cloths can be used to protect any plants that are showing signs of suffering from too much sun. Plants that get hit by the hottest temperatures of the day in the late afternoon may particularly benefit from shade.
Hamby said the spring planting season is about over. Tomatoes and peppers are two of the most popular plants for home vegetable gardens, and they really like the sun. For plants that are more shade loving, and in particular those in pots that tend to dry out faster than plants in the ground, consider moving them into the shade. When you move any plant from shade to sun, please transition the plant slowly to prevent shock. Plants can get sunburned, just like people.
During this excessive 90° heat for plants in full sun, she recommends watering both plants in the garden and pots every evening.
“If you can’t do it every evening, make sure to do it every other evening,” she said. “You can almost always tell if a plant is too wet or too dry because it will wilt. Plants in pots, you can see more easily if that soil is wet. I tell people to let potted plants go semi dry before watering. For plants in the garden, you can dig around in the ground to see if it is bone dry or still wet.”
During the heat, it is especially important to have mulch around plants. Hamby said the old-fashioned way to provide mulch that shades the ground and conserves water is to take newspapers, omit the color pages, and put four to six sheets next to plants or in the middle of rows, and cover with several inches of organic straw. This also keeps weeds out and is a great basis for an earthworm bed.
She recommends green materials like grass clippings be added to the compost instead of immediately put around plants because green materials heat up as they compost. Some people put black plastic around plants, but that needs straw or something else on top of it to prevent excessive heat.
“Lots of people want low or no maintenance, so your soaker lines really, really help,” Hamby said. “It is best to have those soaker lines under the organic mulch or straw. You can use a timer and turn it on ten or 15 minutes every night. That saves a lot of water and time.”
She also cautions people about the type of wood mulch they purchase.
“The reason we only sell aromatic cedar mulch for landscaping is that aromatic cedar is the longest lasting and it repels insects,” Hamby said. “We switched over from cypress mulch from the Gulf Coast after Hurricane Katrina because all the cypress mulch was infested with termites. All the dyed mulch you get from chain stores is made from wood pallets and has chemical dye agents. Anyone who goes organic should use other products.”