By Sommer Cartier, for Let's Talk Plants! May 2022.
If you’ve ever cared for a garden during the late summer months in San Diego, you know the weather can become scorching hot, making it tough for plants to thrive. When temperatures rise as they do in July and August, plants become increasingly vulnerable to heat. The good news is there are several practices you can put in place to protect your garden from the heat and keep it productive and happy well into the Fall months.
1. Practice good soil management –
Add lots of organic matter, such as compost or worm castings, to help prevent the soil from drying out. Organic matter acts like a sponge, retaining moisture for longer periods of time. It also feeds the soil and its microbiome, allowing plants to utilize nutrients more easily. These conditions lend themselves to a healthier, stronger plant. And, just like humans, healthy plants are better equipped to withstand stressors such as heat exposure, disease and pests.
2. Water deeply, thoroughly and routinely –
This encourages roots to grow deep and develop a healthy strong root system. Having deep roots allows for the plants to reach further for water and nutrients during times of scarcity. Plants with healthy root systems are more resilient and more likely to withstand heat.
3. Provide shade cover –
Give your plants a much needed break from the heat by providing a temporary shade cover. Agribon, which can be purchased at your local gardening store, is a very effective and easy material to work with. You can also upcycle materials from around your home such as an old bed sheet or a large umbrella. When choosing a material, make sure it is light in color. Darker materials absorb heat from the sun and can burn the plant foliage. When installing your heat cover, be sure to suspend it several inches above the plants to allow for air to circulate and plants to breathe.
4. Mulch –
Mulch is one of the easiest and most effective ways to protect your garden during a heat wave. When spread across the surface of the garden, mulch can help to keep the soil temperature low by locking in moisture. Mulch comes in many forms. Some examples include wood chips, grass clippings, dried leaves and straw. There are several options to choose from. If looking to keep it simple, select a material that is readily available or already in your yard.
Before applying the mulch, give the garden a deep watering. Once the soil is thoroughly moist, spread the mulch across the surface about two to four inches deep, depending on the material you’re using. Make sure to check the soil moisture regularly by pulling back the mulch and reaching two to three inches into the soil. If the soil feels dry, you will need to water more thoroughly to be sure the moisture penetrates the mulch barrier and seeps down into the soil.
Hopefully these simple but effective tips will help you get a jumpstart on the summer heat. There are several things you can do now to help prepare you for whatever weather summer brings and ensure you have a successful and productive season.