By Bill Sublette
Piedmont Master Gardener
Gardeners don’t need a weatherman to know it’s been a dry year in our area. Stats from the National Weather Service confirm what we’re seeing in our yards: total precipitation is nearly five inches below what we typically receive by this time. As you reach for the garden hose to make up for Mother Nature’s shortfall, keep these pointers in mind to ensure you’re using water efficiently and effectively.
Gauge your water use. In general, established gardens need an inch of water per week. A simple tool recovered from the recycling bin—the tuna can water gauge—will help you meet this target. Bury an empty tuna can up to the rim in the garden and check it as you are watering. When it fills up, you have given your plants the water they need for a week with no rainfall.
Go deep and aim low. Instead of watering lightly every day to reach the weekly one-inch mark, water deeply and less often. Deep watering should reach at least four to six inches into the soil and will build strong root systems that make plants more drought resistant. Aiming the nozzle toward the base of the plants will help deliver water to the root zone and will minimize wetness on foliage, which can increase the risk of fungal diseases. But don’t overdo it. Persistently soggy soil will rob plant roots of the oxygen they need.
Reach in. Before going back to the spigot for the next watering, make sure it’s really needed. With bare fingers, dig three to six inches into the soil to test for dryness. Or try this: if the soil can’t be formed into a ball, it’s too dry to provide water to plant roots. It’s time to water again.
Water early. Irrigate your garden in the morning—ideally before 9 a.m.—rather than during the heat of the day, when a lot of the water will be lost to evaporation. Watering in the evening will also avoid excessive evaporation, but foliage is likely to remain damp through the night, making plants more vulnerable to diseases and other problems.
Apply mulch. A two- to three-inch layer of organic mulch, such as shredded leaves, bark, straw, or even grass clippings, will help keep garden soil moist and cool on hot days while suppressing weeds that compete for water.
But What About My Poor Lawn? Right now, your parched lawn is probably losing color and may look like it’s dying. Don’t panic.
During a long summer dry spell, lawn grass enters a state of semi-dormancy, directing energy to its crowns and roots rather than its leaves. Under these conditions, raise the mower deck to a higher setting (if mowing is even needed) and resist any desire to apply fertilizer. If you’re worried your grass may have died, give it a tug. If it doesn’t break loose, it’s still alive. It will green up when cooler and wetter weather returns.
What to do in the meantime? An established lawn composed mostly of cool-season grasses, such as tall fescue, can withstand three to six weeks of dry conditions without watering. Warm-season grasses, such as Bermuda grass and zoysia grass, are even better at surviving in hot, dry weather and can get by without irrigation. So if you are willing to live with the crunch of dry grass under your feet, there is no need to water your lawn right now. If you insist on it, here are ways to reduce waste and improve results.
Water only as long as needed. As in the garden, the rule of thumb is to apply between one and two inches of water a week to your lawn, minus any rainfall. To reach this benchmark, use a variation on the tuna can technique. Place several cans around the lawn, and time how long it takes to fill the cans a half inch, If rainfall isn’t measuring up, water for that length of time twice a week.
Get to the roots. Again, water in the morning to avoid evaporation, and water deeply to reach down to the roots—three to six inches into the soil. Frequent, shallow watering encourages weeds rather than a healthy lawn, while also increasing the risk of disease and insect problems.
Water your lawn, not your driveway. Adjust your sprinkler to keep water on your lawn and away from paved surfaces, where it can become runoff that carries road pollutants to nearby waterways. If water starts to run off your lawn while you are irrigating, reduce the flow or take a break. Let the water soak in, and resume watering later.
Create a Water-Wise Landscape. The easiest way to conserve water is to create a landscape that uses water efficiently.
Improve the soil. Adding organic matter to the clay soils so predominant in our area will help them absorb water faster while reducing runoff and erosion. Each year, work in two to three inches of compost or shredded leaves into your garden soil.
Choose the right plants—particularly native plants. The native plant database on Albemarle County’s website (Albemarle.org) will help you identify natives that can tough it out in dry conditions once established. Among them are perennials that are magnets for pollinators, such as butterfly weed, Joe Pye weed, black-eyed susans, and narrowleaf mountain mint. You’ll also find drought-tolerant native shrubs, such as New Jersey tea, arrowwood viburnum and fragrant sumac. If you do select plants with high water demands, group them together so they can be watered easily.
Limit the size of your lawn. Plant turf grass only where it will be beneficial, such as play areas for children, and select turf grass species suitable for our climate. The Virginia Cooperative Extension publication Creating a Water-Wise Landscape offers more ways to make your yard and garden more water-efficient. You can find it by searching for Resource Number 426-713 on their website, resources.ext.vt.edu.