Photo: Gray Catbird, Steven Biegler/Audubon Photography Awards
Alyssa Ford Morel
Hot and humid have long been a hallmark for Virginia’s summer months. With the inexorable progress of climate change, our weather gets hotter, and, frankly, wackier. We used to be able to count on regular rain that would perk up plants and cool down temperatures, but now the storms are more sporadic and dramatic. We’ve had “heat domes” and “flash droughts.” The impact on landscapes and the creatures with whom we share our environment can be devastating.
When the rain doesn’t fall and temperatures are high, the living members of our environment react. Plants open their stomata (tiny openings in their stems and leaves) to increase transpiration and cool down. But when there is no moisture for their roots to take in, they close their stoma, and leaf temperatures rise. If the heat and drought continue, plants die.
One way to help plants thrive during stressful periods is to start with optimal conditions. Nature has designed plants to drop leaves, which then decompose, providing a rich organic layer that holds moisture and insulates roots from changing temperatures. That organic layer in turn is home to many small creatures that create the web of local biodiversity. “Leave the leaves” is a practice reflecting a modern understanding of how nature works.
Rain garden, USEPA, Public domain, via Wikimedia Commons
There are several ways to “harvest” the rain that falls on our property and stretch out its usefulness. Rain barrels and cisterns collect and hold water for later use. Simple systems rely on gravity to distribute the water via hoses or watering cans, but more complex systems use pumps. Rain gardens are specially designed depressions that collect excess water, using permeable soil and native plants to recharge the ground water and avoid mosquito breeding.
During the ever more frequent gaps between rain events, there are also ways to be more conscientious when watering conventionally. We reap long-term benefits by placing plants with similar water needs together. Grouping moisture-loving plants together, particularly in an area that tends to be moist, means supplemental water will go further and not be wasted. The time of day during which we water also makes a difference, with early morning being the best time since plants can absorb the water and be ready for a hot day, as well as avoiding the moisture-loving funguses and mildews that establish in the damp overnight. Watering less frequently but more deeply is also best practice. Water that penetrates deeply will encourage deeper roots on plants. The further under the ground-layer water goes, the less likely it is to evaporate in the heat of the sun.
Even established trees are not immune to the challenge of heat and drought. They may not show the stress quickly, but can become weakened by the ordeal. A slow drip for a few hours on a venerable tree can keep it viable for the years to come.
Wildlife also will benefit from supplemental water. Birds use water to lower their body temperature, either by swimming or bathing, and of course, they drink water to stay hydrated. Birdbaths and fountains can be extremely popular and are sometimes life savers in hot weather.
Depending on birdbath placement, various mammals, amphibians, even reptiles and insects may also visit. It is important that bird baths be kept clean and the water changed regularly to avoid disease transmission and mosquito breeding.