Gardening Tips in Extreme Heat

  • Difficulty Rating: Beginner
Gardening Tips in Extreme Heat

Extreme heat merits triage treatments

In 2011, much of the United States suffered extreme heat and drought. Due to watering restrictions, gardeners were forced to make choices about which plants to water and save.

How much to water and ways to help plants survive extreme temperatures takes real thought and can test a gardener’s mettle. Here are some good ways to cope.

Plant in spring and fall

  • Don’t plant once heat starts to build in late spring.
  • Also, try not to be tempted by those plant sales at your local garden nursery in August. If the nursery is trying to unload the rest of their stock, it’s not the best time to plant.
  • Consider planting trees and shrubs in fall to give them growing time before the following year and high temperatures.

Water deeply and less frequently

  • When watering during drought and extreme heat, remember that getting plants through the worst of the season is your goal.
  • In extreme heat, it’s difficult to see plants die, but have a triage plan to save only the most expensive plants, or those most important to the garden’s design and the gardener.
  • Use drip irrigation or soaker hoses. There are a variety of different types of drip irrigation available to gardeners. Not that many years ago, some systems were only used by commercial properties, but with changes in climate and demand, many systems are now offered for the home gardener too.
  • For larger gardens, contact an irrigation specialist.
  • For smaller spaces, use soaker hoses, or install a system from the hardware store or nursery.
  • Container gardens can also benefit from drip irrigation in hot climates because plants are watered more efficiently.
  • Try ollas (pronounced “oyas”). Ollas are unglazed terra cotta containers buried in the ground up to their bottle-like necks. They are used for deep watering in hot and dry climates. Water is poured into the neck of the olla and left to leach out to plant roots. Ollas can be made with five gallon buckets with lids. Before submerging buckets partially into the ground and filling with water, poke small holes into the bottom and sides of the bucket. Ollas work well where watering restrictions are especially onerous because hand watering is still often allowed. You will need to fill ollas a couple of times a week during the driest part of the season.


  • Nursery owners and garden writers often encourage mulching the garden, but how much mulch should one use, and what kind?
  • When choosing mulch, use only biodegradable materials that decay over time.
  • Two to three inches of mulch should be plenty for the growing season.
  • Don’t put mulch up against trees because it can damage the tree from rot.
  • Also, mice and other vermin may create nests in the mulch and chew on the tree’s bark.
  • Wood mulches make a fine protective layer as long as you only place them on top of the soil letting the wood decay in place.
  • Don’t mix wood mulch, especially fine particles, into the top layer of soil, or it will pull nitrogen from your soil as it decays.
  • Choose wood mulch that isn’t “green” and not from endangered trees.
  • Use the right tools for the job, like the Fiskars Ergo Garden Fork, for moving your mulch around.
Fiskars Steel D-Handle Ergo Garden Fork fork in leaf piles
  • Shredded leaves are also an excellent choice, but they break down faster than wood mulch and may harbor weed seeds. However, earthworms love shredded leaves and will make your soil more friable and fertile with their castings. If leaves are not hard and fibrous, leave them in place to decay. Oak and other tough leaves should be shredded and allowed to decay a bit before placing on the garden. Soils topped with shredded leaves will soon be crumbly and easy to plant.
  • Finished compost is good to use as mulch, but it breaks down quickly. Compost can be made at home using the Fiskars Eco Bin Composter or purchased in bulk or in bags. Make sure any compost or other mulches used in the garden have not been treated with persistent herbicides.
  • Weed-free straw is good mulch and is often used in vegetable gardens. It packs down and hold weeds at bay. Make sure to use straw instead of hay to prevent seeds from germinating.
Plants can become living mulch when planted close together.
  • Plants can become living mulch. When planted close together like the ones at Bustani Plant Farm in the photo above, they shade each other’s roots and keep weed seeds from taking hold.

Shade Cloth

Shade Cloth is often used in vegetable gardens in hot and dry climates. It helps protect plants from intense sun. If you decide to use shade cloth, consult your local cooperative extension service for the shade percentage used in your area.

Grow plants that don't ask for much.

Choose and grow plants that are drought resistant and can handle the heat. Some suggestions are:


Ornamental grass in summer
  • Ornamental grasses;
  • Agastache, salvia and other sun-loving perennials;
  • Plants with silver foliage like lamb’s ears, artemisia, dusty miller, ‘Silver Falls’ dichondra (used in hanging baskets or as a ground cover) and curry plant—not culinary curry; and Sedums and cacti.

Try the tips above and make your job easier in extreme heat and drought conditions. Even if your area doesn’t experience these extremes, these tips are all good garden practices and will help your garden survive whatever the climate delivers.