Usually, gardeners are concerned about too little sunlight. We plant seeds in our gardens in an area located in full sun or at least six hours of sun per day. However, those gardeners who are located in the South are facing increasing heat waves and often with extreme temperatures of over 100 degrees over an extended period of time. Climate change has made even the Northern areas susceptible to heat waves. Most vegetable plants will be stressed in temperatures over 95 degrees, and many will not survive temperatures of 100 degrees or more. When the plants become stressed, they may start to drop their blossoms and even leaves. The leaves and the fruit can become sunburned. The plants will have yellowish white areas on the leaves and fruit that signals tissue death. The growing ends of the plant will stop growing and start to wilt.
Along with the extreme heat comes increased evaporation from the soil and the plant itself. Your plants will stop growing and will not set any fruit. If the heat is going to last more than a couple of days, the gardener must take action to lower the temperature for their plants. The best way to do that is to provide shade. Shade can drop the temperature as much as 10 degrees, which can make the difference in your plants’ ability to produce fruit and, in extreme cases, even the survival of your plants can be at stake.
There are several ways to provide shade for your garden. If you know your area has recurring heat waves each year, you may want to plan ahead and even provide a permanent solution. If you are new to this type of heat or this is an occasional problem, you may be interested in a less permanent solution. Here are a few suggestions on how to provide shade in your garden.
1. Dress it Up With Shade Cloth
Shade cloth is a lightweight fabric that can block the sun’s rays. It is available in dark or white color and in varying degrees of shade. Typically, the shade cloth is draped over some type of frame such as fiberglass or poly hoops. This will allow the air to circulate around the plants. You will want to protect the plants from midday sun and also the setting sun. The early morning is the coolest part of the day and the plants will not require as much protection.
You can also use tall stakes on the southern and western sides of your garden and stretch the shade cloth between them. Attach the shade cloth to existing trellises to protect the vegetables growing on the trellis.
If you are using dark shade cloth, do not allow it to touch your plants. The dark color will absorb the heat and transfer it to your plants. If you are using white shade cloth, your plants will not be hurt by being in contact with the shade cloth, as the white cloth will reflect the heat away from the plants. Your shade cloth can reflect as much as 85 percent of the sunlight, lowering the temperature while holding in the humidity.
Include shade cloth when you purchase your garden supplies so you are prepared when you need it.
2. Add Some Fencing
If you live in the South and the heat is an annual problem, you may want to consider a permanent open weave fence along the south and west exposure. The open weave will allow air circulation and some sunlight in your garden and provide the temperature relief by shading the garden from the worst of the sun’s heat.
3. Functionally Decorate with Umbrellas
A garden umbrella is a good solution for a temporary problem. It can be moved to the location where it is needed and easily removed when the heat subsides. An advantage of the umbrella is most can be angled to provide shade where most needed. Some umbrellas do block all the sun so make sure your plants get some sun in the morning when it is cooler. Also, be prepared to close the umbrella or even remove it if there is a strong wind that could topple your umbrella and damage your growing plants.
4. Plant Sunflowers
Plant a double row of sunflower seeds along the southern and western edges of your garden. Sunflowers can grow to over 12 feet tall, depending on the variety of seed you purchase. The sunflowers have large leaves covering the stem and culminating with a beautiful and large flower head. By planting seeds in a double row, you will block most of the sun’s rays to protect the more heat-sensitive plants below. This is a win-win situation as the sunflowers will attract pollinators, feed the birds and provide exceptional beauty all while doing the job of providing shade in your garden. Any tall plant, such as corn, will work as well.
5. Plant Sun-Tolerant Vines
If you know every year the heat is an issue in your garden, plant seeds of a sun-tolerant vine like hyacinth vine or Malabar spinach on a trellis. The vines will continue to do well, and by placing your trellis on the south or west side of the garden, the less-tolerant plants will be protected.
6. Try Paper Bags
If you are worried about your peppers or even the fruit on your trees, you can cover the fruit and protect it by placing a bag over the fruit. This will work if the fruit, like a tomato, is held on the end of a branch. Slip a bag over the tomato and staple or tape it to hold it in place. This alternative may protect your produce if a shade cloth is not possible.
7. Spread some Mulch
The importance of a good layer of mulch cannot be overstated. While it won’t directly shade the plant, it will shade the soil the plant grows in and the root system as well. Mulch will keep the soil temperature lower and hold in the moisture, which is so important during a heat wave.
With a little planning, your garden will be ready for any possible heat wave. Plant seeds according to a plan that includes protection from the heat wave temperatures that may come this summer.