Protecting Plants from the Heat

Summer is just getting started here in Maryland…but the sun is already at full force. We are expecting record-setting heat this week. Here are some tips and tricks to keep your plants happy in the heat.

1. Recognize stress

An in-ground pool surrounded by lush landscapingMany stressed plants look thirsty. Green foliage turns grey and droops; blossoms and leaves fall to the ground in a desperate attempt to save the shrub. A deep watering often brings a plant back or at least saves it so it’ll bud next year.

But if leaves are crispy, or the plant continues to look parched in the evening, then it’s reached a permanent wilting point: this plant will need to be removed and replaced come to Fall.

2. Triage. Stat!

In heat and drought, save what you can in this descending order:

  1. Newly planted shrubs and trees, vulnerable and pricey landscaping
  2. Perennials: Cut blossoms and stalks, which gives plants rest and raises chances of returning next year.
  3. Established trees and shrubs, at least two years old, which have deep roots.
  4. Container plants: Move them onto a porch or under a shade tree.
  5. Vegetable gardens
  6. Lawns

3. Watering 101A large patio surrounding an in-ground pool

Here’s a watering rule of thumb: Water deep, not often. Water should reach 8 to 12 inches down, creating a well of water for plants and trees to draw upon in high heat. To determine if you’ve reached your mark, press a large screwdriver into the soil: If it meets resistance, keep watering.

Hand-watering with a garden hose and aerator is best. Count to 10 as you water the base of plants. Move and repeat. If you have lots of property to water, then use a sprinkler, but adjust it so it doesn’t waste overspray on driveways and walkways.

Water in the early morning: Not 7 a.m. when you usually roll out of bed, but when the sun rises at 5 a.m. or 6 a.m. However, don’t get fixated on the water in the morning. If water restrictions require only evening watering, soak ‘em good and don’t fret about fungus forming on leaves that stay damp throughout the night: A little powdery mildew won’t kill your shrubs, but dehydration will.

4. Mulch is your friend

If you didn’t mulch in spring, do it now. Mulch will keep moisture in the ground and suppress weeds, which compete with landscaping for water. If you haven’t mulched, water thoroughly, then add mulch to a depth of 3 to 4 inches.