Gardening: Help plants cope with summer heat in spring

Nancy Szerlag
Special to The Detroit News
View Comments

Mother Nature has not been kind to me this year. Spring was not only very late in coming, it lasted not more than a week. The weather this Memorial Day seemed more like the Fourth of July, which is not bad if you’re sitting on a beach, but I spent the holiday planting annuals in the OPC garden. Ugh.

I take special care when planting in steaming hot weather. A day or two of heat is one thing, but our extended forecast looks brutal.

Water is a big key to success when planting in heat. If Mother Nature doesn’t cooperate, I water the planting bed well a day or two before planting. When planting containers, I pre-moisten the potting soil by mixing 3 parts potting medium to 1 part water, mix it up and let it sit overnight.

Dry garden soil and potting soil will suck the moisture out of the plant’s root ball and may also destroy the fine root hairs that take up moisture for the plant. While the newly planted specimen may not die, it will begin life in the garden in stress.

To make sure the root balls of the plants are well watered before planting, I soak them in a large plastic sweater box filled with several inches of water until no bubbles emerge. In hot weather I use my “rescue remedy” mix as a soaking solution — one ounce of Neptune’s Harvest Seaweed Plant Food (liquid kelp) and 1/4 tsp. of Superthrive vitamin solution mixed in 1 gallon of water. Both of these products help plants deal with stress caused by excess heat, drought and wind.

No amount of fertilizers will help while these conditions persist, and may in fact do more harm, however, there are some other things you can do.

After planting, mulching the surface of the soil around plants planted in the ground or in containers will help retain soil moisture and cool surface roots.

Shading plants from the sun is another option. On a 90-degree day, the curling of leaves even when the soil is moist is a good indication of heat stress. Temporary screening made from 30 to 50 percent shade cloth, lattice, floating row covers or even old screens are good options for both flowers and veggies. For tips on how to construct and use them Google “how to shade the garden in hot weather.”

Fancy beach umbrellas make cute makeshift shade covers on blistering hot days.

Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to and click on Ask Nancy. You can also read her previous columns at

View Comments