Gardening in Extreme Heat: Stay Calm and Cool and Garden On

June 30, 2024

Extension Master Gardener Recommended Best Management Practices

By Nancy Brooks, Extension Master Gardener

First, care for the gardener

fluid pouring in pint glass — Photo by Pixabay on Pexels.com

The New York Times reported on June 17, 2024 that “Heat already kills more people in the United States each year than hurricanes, floods and tornadoes combined, according to the National Weather Service.”

Garden early in the day when it is cooler.
Wear a hat, sunscreen, and sun protection (UPF-rated) clothing.
Hydrate.
Stop at the first sign of discomfort.

Best Practices

Packera aurea (Golden Ragwort) and Parthenocissus quinquefolia (Virginia Creeper) intermingle to create a green mulch — Golden Ragwort and Virginia Creeper intermingle to create a green mulch to cool the soil, maintain moisture, & outcompete invasive English Ivy.
Photo © Nancy Brooks

Choose the “right plant, right place,” in order to take advantage of garden microclimates—hot areas, light angles and moisture sinks, sun or shade, wet or dry, when planning your garden layout. Select plants for the landscape that will grow in the existing soil and plant hardiness zone.
Achieve a low maintenance garden by planting native plants that minimize ongoing labor and increase habitat for wildlife. Avoid planting invasive species.
Group plants with similar needs (water, fertilizer, sun) for easier maintenance.
Use plants or mulch to conserve water, suppress weeds and prevent soil erosion.
Create shade for newly planted plants, using old shower curtain liners to create tents or sails.
Move container gardens into the shade so that they don’t dry out as quickly.
Mulch and cultivate green mulch.

Irrigation

Irrigate landscape plants deeply and infrequently, at a rate of 1″ per week. Avoid runoff.
Light, frequent watering encourages shallow roots and makes plants more vulnerable to drought.
Irrigate early in the morning, rather than late at night, to minimize evaporation losses and to minimize pests that thrive on wet foliage.
Calibrate your irrigation system to deliver approximately 1 inch of water per week.

Compost

Use compost to improve soil structure and fertility in lawns and gardens.
Prevent erosion by maintaining vegetative cover using mulch, and correcting drainage problems.
In the fall, spread about 2 inches of compost over your entire garden and work it 6 to 8 inches into the soil.
Mulch trees only 2–3 inches high, and 4–6 inches away from the trunk of the tree/shrub. No volcanoes!

a person cutting grass with a lawn mower — Photo by Magic K on Pexels.com

Turf

Skip mowing in extreme heat and let the grass grow deeper roots.
Let cool season grasses go dormant in summer.
Follow the 1/3 mowing rule–Never remove more than one-third of the leaf blade at any mowing event.
Return grass clippings back to the lawn—it counts for up to 30% of a lawn’s nitrogen requirements for the year.

Wildlife

Change water frequently in the birdbath. Use mosquito dunks. Add a rock for perching.
Leave a low dish of fresh water on the ground for ground-living creatures. Use mosquito dunks, Include an escape route like a rock.