Outwitting the late summer heat

April Fool’s! Oops! It’s August. Well, the thunderstorms are playing jokes on gardeners. Lots of thunder and lightning and just enough rain to fool us into thinking we don’t need to water our plants as often.

Most of us are in the late summer doldrums. It’s too hot to enjoy being in the garden. The mosquitoes mob us every time we go outside. We even have to contend with sticky humidity without the relief of rain. Yet we persevere, though the plants appear as discouraged we are.

Lawns

The grass in our lawns is miserable in this heat. It is turning yellow and revealing bare spots. Rain plus irrigation barely seem to keep it alive. There are several reasons for the patchiness of lawns, in addition to the heat. Some species of grass go dormant in hot dry spells, and extra irrigation may not make a difference. The storms and our summer activities have compacted the soil, damaging roots. It’s also possible grubs have attacked the roots. 

Luckily, compaction and grubs are manageable problems. For compacted soil, the secret is to aerate the lawn. There are machines and special tools for this task, but several tools in your garden shed will work just as well.

Rake the surface of the soil digging into the grass to remove the thatch of old grass and leaves and roughing up the soil. This helps break up the soil surface, so water can seep into the ground, rather than running off. A digging fork poked into the bare spots to loosen the soil surface, creates openings for air circulation and allows water into the soil. 

If you have a circular dead patch, check for grubs. With a shovel, cut a 12-inch area of soil about 3-4 inches deep. Flip the soil over to look for grubs, which eat the roots of plants, especially in lawns. If you find six or more grubs, it is time to treat the lawn with a product for eliminating grubs.

Trees and Shrubs

Even with their deep roots, trees can show stress at this time of year. Their large canopies of leaves, which transpire lots of water during a hot day, require extra water applied to the soil slowly over an area that stretches from the trunk to the outer edges of the canopy every week or two. Shrubs also require additional irrigation for the same reason.

Flowerbeds

Flowers are so varied in their needs, it’s hard to keep all of them thriving and blooming during the hot months. Many annual flowers will go to seed and die once it gets hot. Don’t despair, as the seeds will sprout in the late fall or spring for next year.

Perennials need to have a slow soak for their roots, which expand more each year. Even our native perennials need some extra TLC when we have so many extremely hot days. While tending the flowers, this would be a good time to deadhead or cut back plants, which decreases the leaf surfaces, and collect seeds.

Vegetable Gardens

These are the most difficult plants to pamper through the heat. So many plants, such as tomatoes, go dormant when it is too hot. They may bloom, but usually do not set much fruit when the temperature is more than 85 degrees.

Some plants with large leaves wilt on hot days, since the leaves transpire water more quickly than the roots can draw it in. Now is the time to add extra mulch and/or compost to keep the soil cool, hold moisture and provide additional nutrients.

Current research shows irrigating in the evening is more beneficial to your garden. Plant roots have all night to replenish the water in the leaves before the heat arrives the next day. So as the temperatures drop a bit in the late day, take the opportunity to cool you and the area around the house by irrigating the garden. Then duck back indoors to wait for pleasant fall days, when it is more fun and more productive to be in the garden.