Heat waves and drought are now par for the course every summer, just about everywhere on the planet. Every gardener has experienced first hand the devastating effects extended periods of high heat can have on their beloved plants. But with a little careful planning in your garden design, you can have a beautiful, lush garden that makes it through drought and heat relatively unscathed.
6 tips to protect your perennial garden from heat extremes
1: Most ornamental gardens start at the edges of the home, and buildings affect sunlight in unusual and unexpected ways. To minimize sun scorch and heat stress, match the right plant to the right amount of light.
2: Before planting anything, first look to see where and at what time sunlight shines on each garden area. Full sun plants like lilacs and sunflowers need a minimum of 6 hours of direct sunlight each day. If an area receives less, then that part of your garden is considered one of the varying degrees of shade and should be planted appropriately. The converse is true as well – hostas planted in anything but shade will take a battering from sunlight in July and August.
3: Consider planting a tree on the southwest side of your property and build a shade garden around the tree. Dispense with mulching and instead plant hosta, bugleweed, Sweet Woodruff, Wild Ginger, Toad Lily and other shade-loving groundcovers. Plants at the base of the tree will keep the soil around the tree insulated, just like mulch.
4: Shrubs and flowers that benefit from light shade should be planted on the east side of trees, so they’ll receive late afternoon shade to keep them cool in heat waves. That shade could be the difference between plants dying or surviving a heat wave, as they’ll get relief each day when the heat is cruelest.
5: Design your garden so heat and sun-sensitive plants like hydrangea receive shade from tall plants, shrubs, or trees. Plant pansies and other flowers that dislike intense sunlight and heat at the base of shrubs that throw afternoon shadows to give the flowers relief.
6: Always use native plants in an ornamental garden, as they’ve adapted to your local weather conditions. The same goes for trees. Lists of native plants for your region can be seen at wildflower.org and plantnative.org.
5 tips to protect your vegetable and fruit garden from heat extremes
Many of the same concepts described above for planning and protecting an ornamental garden are valid for your vegetable garden, too. But you only get one shot each season to get your vegetable garden right, because food crops subjected to early-season heat waves can become a complete loss quickly. On the flip side, most food crops need plenty of sun to produce the things we love to eat. Striking the correct balance can be tricky.
1: Plant tall crops like corn and tomatoes so they provide shade for leafy greens, cabbage, broccoli, and shade loving herbs like parsley and cilantro. This is known as companion planting, which also helps with pest control.
2. A shade tree on the west side of your vegetable garden can provide critical afternoon relief during a heat wave, but make sure to plant fruits and vegetables which tolerate or love intense sun farthest from the tree.
3. Use portable or temporary shade like row covers (pictured above). Allow enough room to install posts to hang shade cloth when necessary (available online or at hardware stores). Shade cloth is an effective way to keep sun from scorching your sensitive plants (sun scald) and to lower their temperature just a bit. Large, container-planted trees can serve the same purpose, especially if they’re mobile.
4. Allow space to install row covers or hoop tunnels to grow sensitive plants. These have traditionally been used as season extenders to keep plants and soil warmer in early spring and fall. But they can also act as shade for low growing plants like leafy greens. Row covers can lower air temperature around plants by as much as ten degrees.
5. The best defense against a heat wave is to act early and know what’s coming. Inspect your plants at least once a day and watch for signs of heat stress as described in the first part of this series.
Read part 3: Tips for watering your garden during a heat wave.
Read part 1: How heat affects garden plants.