Some Like It Hot (and Dry) — Thoughtful Gardeners Learn to Love Plants That Can Tolerate a Drought

By Christine Arpe Gang / Special to The Commercial Appeal

It’s been a great year for cacti.

Hot and dry weather with a few sporadic showers is what the prickly plants thrive on.

But since most of us don’t have desert gardens, more water from the heavens and less from hoses is our fervent wish.

Rainfall earlier this week was welcome, but did not signal an end to dry conditions, said Todd Beal, meteorologist with the National Weather Service.

“It didn’t make a dent in the drought,” Beal said.

With a shortfall of 12 to 13 inches of rain so far this year, Shelby County is in a “moderate drought,” according to the weather service.

March, April and May, which are normally times for lots of rainfall, were the driest since 1931, the earliest year for the weather service’s computerized climate data.

As a three-year dry spell turns into a serious drought with little relief predicted, it’s time to think about plant choices and irrigation practices that produce great displays while conserving water and energy.

Chris Cosby, greenhouse manager at the Memphis Botanic Garden, is pleased with the performance of the

drought-tolerant plants installed less than a year ago in front of the Rick Pudwell Horticultural Center there.

The trough-like planter, an inhospitable environment sitting on top of hot asphalt pavement, is filled with a mix of sharp sand and compost. The botanic garden’s compost contains elephant dung, leaf mold and bits of clay.

Plants with gray to blue-green foliage tend to be more drought- tolerant than those with deep green leaves. So for the planter, Cosby selected Fireland, a yarrow with flowers that emerge red, fade to pink and then turn golden; Firewitch and Arctic Fire dianthus; blue mound rue with yellow flowers and big-leafed Helene von Stein lamb’s ears, which has far fewer flowers than the most common type.

Ornamental grass, such as Adagio miscanthus and Mexican feather grass, also thrive in the trough’s dry conditions.

Included in the small grouping are creeping phlox, Tiger Eyes sumac and two yuccas – Golden Sword with yellow and green leaves and red yucca, with red flowers on tall stems that attract hummingbirds.

Just as it is difficult to trade a gas-guzzling SUV for a subcompact, gardeners will not part easily from heavy drinkers, such as hydrangeas, azaleas, hostas and lawns. And no one is suggesting that they should, because normal rain patterns will return one day.

Grouping plants

When designing or redesigning beds, it’s a good idea to group plants with similar water needs, said Carol Reese, ornamental specialist at the University of Tennessee Research and Education Center in Jackson.

“I plant my cannas and elephant ears together so I can keep them moist and lush,” Reese said. “My drought-tolerant plants like yuccas, grasses, echinaceas (coneflowers) and black-eyed Susans are together, too.”

When she has to water her beds, she likes to wet the surface of the soil for a short time, wait awhile and then go back to give it a thorough and slow soaking.

“That softens the surface of the ground to make it more receptive to the water,” she said.

While it’s more efficient to water in the morning or evening when it is cooler, gardeners should not be afraid to water their plants whenever they have free time, she said. Drip irrigation or soaker hoses are the best way to water regularly, because moisture isn’t lost to evaporation as it is when water moves through air. And the water is directed to the root zones of the plants, not on the leaves, where moist conditions can lead to fungal diseases.

Reese also likes to keep a bucket or container of water deep enough for dipping container-grown plants to completely saturate their root zones.

She moves containers in full sun to a place where they get shade for half a day.

Trees and shrubs

Many perennials and annuals tell us when they are thirsty by wilting. But trees and shrubs are more difficult to read. When they start looking dry and wilted, it may be too late to revive them with water.

“It’s important to give trees one inch of water per week until we break out of this dry spell,” said Dr. Mark Follis, owner of Follis Tree Preservation (formerly Bluff City Tree Preservation). “Japanese maples are especially stressed because they were hurt by the frost (at Easter), too.”

Water both newly planted and mature trees and shrubs.

Damage from the late spring freeze limited the ability of some trees to move moisture from the roots up to the limbs, causing dieback in some branches.

“Silver maples and oaks appear stressed,” Follis said.

A great many Bradford pear trees, which were stressed by both the freeze and the drought, have fire blight disease, Follis said. Crabapples, cotoneaster, pyracantha and flowering quince are also susceptible to the disease, which causes branches and twigs to have a black, scorched appearance.

Infected branches should be cut off at least 6 inches below the infected area. To keep the disease from spreading, sanitize pruners and saws after every cut by spraying with Lysol and wiping the blade with a new paper towel. You can also put a 10 to 20 percent solution of household bleach in a spray bottle for sanitizing.

Lawns

To keep lawns looking green and lush in a drought, you have to be willing to provide them with at least an inch of water per week.

Bermuda and zoysia, the most common grasses for sunny areas, are both drought-resistant. Without regular water, they may turn brownish and go dormant but usually will not die.

“A well-established Bermuda grass lawn is self-healing and resilient,” said Bill Wyatt, extension agent for Madison County. “I can’t ever recall one actually dying and my recollections go back to 1980 when we had temperatures above 100 for many days and dryness, too.”

Zoysia is also resilient, but fescue, a turf type used for shady conditions, needs water to survive.

Fescue, which grows in cool weather, is stressed in the summer even when there is adequate rainfall, Wyatt said.

The good news is dormant Bermuda and zoysia lawns require much less mowing than active lawns. Raise the mowing height to 2 to 2 inches and be sure never to remove more than a third of the height of the blades at any mowing.

Don’t fertilize

“I would not recommend that anyone fertilize a lawn in drought conditions unless they are irrigating it continually,” he said. “If you start irrigating the lawn, you need to continue to do it.”

Don’t fertilize perennials and shrubs with high-nitrogen products when it is dry. They may need all of their energy to survive and become stressed if forced to grow.

Organic products that provide nutrients over a long period of time are OK to use.

Be philosophical

Before this three-year dry period began, gardeners and horticulturists remember a particular winter and spring season that was wetter than average. The blooms of the spring-flowering trees and shrubs were brighter and more lush than usual and other plants seemed more vigorous as well.

But there were some problems with fungal and other diseases.

“We have to remember that everything is cyclical,” said Rick Pudwell, director of horticulture at the botanic garden.

But given the problems associated with extremely wet conditions and extremely dry, Pudwell said he would take wet any day.

“When it’s wet, you can compensate by planting higher and leaving off mulch,” he said. “But when it’s dry, you can’t do anything except water.”

Christine Arpe Gang was a staff writer at The Commercial Appeal for 33 years before she retired 18 months ago. She is a free-lance writer. Contact her at chrisagang@hotmail.com

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INSIDE

What to plant: Drought-tolerant plants for your garden.

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