Read the signs before you react
Maryland summers bring stretches of high heat and humidity, and our heavy clay soils swing from soggy to bone dry quickly. The first skill is telling real stress from normal behavior. Many plants wilt at midday as a way to reduce water loss, then recover on their own by evening. That midday droop is not an emergency. The warning sign is a plant that is still wilted in the cool of the evening or early morning. That plant cannot keep up and needs water now.
Watch the leaves. Green foliage that turns gray and droops usually responds well to a deep soak. Leaves that are brown, crisp, and brittle have passed the point of recovery and that growth will not come back, though the plant may still push new growth if the roots survive.
Triage in the right order
When heat and drought hit and you cannot save everything at once, work down this list:
- Newly planted trees and shrubs, which have shallow roots and the most to lose
- Container plants, which dry out fastest and can be moved into shade
- Perennials, where cutting back blooms and stems lets the plant rest and improves its odds next year
- Established trees and shrubs over two years old, which have deep roots and the most reserves
- Vegetable gardens
- Lawns, which are the most likely to be dormant rather than dying
Water deep, not often
The single most useful rule in heat is to water deeply and less frequently. Shallow daily sprinkling trains roots to stay near the surface where they cook. A deep soak that reaches 8 to 12 inches down builds a reserve the plant can draw on. To check your depth, push a long screwdriver into the soil after watering. If it slides in easily you have reached moist soil, and where it stops is roughly your water line.
Water at the base of the plant, not over the top. For beds and shrubs, a slow hose or soaker line beats overhead spray, which loses water to evaporation and wets foliage. Most established plants want about 1 to 1.5 inches of water per week in summer, and new plantings want more.
Time it for early morning
Water between about 5 and 9 a.m. The air is cool, less is lost to evaporation, and leaves dry through the day. If local water restrictions only allow evening watering, soak deeply and do not worry much about mildew. A little powdery mildew rarely kills a shrub, but dehydration does.
Mulch and shade
Mulch is your best defense against heat. A 3 to 4 inch layer of shredded bark over the root zone holds moisture, keeps soil temperatures down, and crowds out weeds that compete for water. Keep it back from trunks and stems. If you skipped mulch in spring, water thoroughly and then lay it down.
For vegetables and tender plants, temporary shade cloth during the worst afternoon hours can prevent scorch on fruit and leaves. Move container plants onto a shaded porch or under a tree during a heat wave.
What not to do in a heat wave
Two common mistakes make heat stress worse. Do not fertilize stressed plants, since pushing new growth in extreme heat burns roots and foliage. And hold off on heavy pruning, which forces tender new shoots at the worst possible time. Wait for the weather to break, then resume normal care.
A little attention during the hottest weeks, deep morning watering, a fresh layer of mulch, and smart triage, carries most landscapes through a Maryland summer with minimal loss. Hometown Landscape can set up efficient watering and mulching as part of seasonal maintenance for properties across Burtonsville and the surrounding area.
Hometown Landscape provides professional landscaping services for homeowners across Burtonsville, MD and the surrounding areas.