Heat waves like the ones we experienced this summer are especially dangerous for our gardens. As well as accelerating plant water loss through transpiration, they also increase soil temperatures, which can damage plant roots. Signs of heat stress in plants include wilting, drying and browning of leaves, leaf drop, dying branches and reduced growth.
So what's a gardener to do? Because water-hungry plants can't uproot and seek out shade and water, there are some steps homeowners can take to help their plants survive sustained periods of 100-degree weather.
Shade Plan
The first steps should be taken even before planting: Be sure to check the sun/shade and water tolerance of your plants. Choose varieties that are tolerant to heat and drought. Don't plant shade-loving plants in direct sunlight and group plants with similar moisture needs. Plan your shade shelter in advance: use existing plants to provide shade for smaller plants. Fences and other structures can provide needed shade during the hottest hours of the day. Be careful when planting next to white walls or similar surfaces: reflected heat and UV radiation can create hot drafts that are harmful to your plants.
You can also create temporary shade by hanging shade “sails” or shade cloth, available at most hardware and garden stores. Burlap or other fabric works just as well. Use plant stakes or tomato poles to support the temporary shade. You can also repurpose an uncultivated umbrella to create shade. A pop-up canopy can also provide shade over a larger area.
