You probably didn’t need a drought monitor or an announcement from the water authority to tell you that we’re in the midst of a drought. And simply walking out the door tells you all you need to know about the extreme heat we’re experiencing. But perhaps a few tips on helping your yard and garden survive would come in handy. After reviewing a number of articles from the nation’s extension services, we pulled together the following:
Watering
You may be aware of this basic watering advice from Virginia Tech, but it bears repeating:
“Watering deeply can help stave off the effects of temperature and drought.
“If gardeners can irrigate or water their gardens, they need to be mindful of a few things,” Byington said. “It is better to water a lot at one time, rather than to just give small amounts of water more often. Watering thoroughly allows plants to develop the deep roots they need to obtain moisture and nutrients from deeper in the soil.”
Gardeners should also be mindful to water in the morning or the evening, but not during the hottest parts of the day, Byington added.
“Water early in the morning to allow plants to get moisture before dealing with the hot day or water late in the evening to allow plants to replenish after the day,” she said. “Watering when temperatures are cool, allowing for less evaporation, works as well.”
— Devon Johnson, Va. Tech News, Heat and dry weather pose problems for landscape plants
When the Arizona Extension speaks about heat and drought, we sit up and pay attention:
A critical element of proper irrigation during our hot summers is timing. It is advisable to water early in the morning, pre-dawn even. . . . It is important to apply the water to the soil before the heat of the day, when rapidly warming soil surfaces can begin to dry and wick moisture out of the root zone. Watering early ensures that the water moves deeper into the root zone, where it can be retained and is accessible by plant roots for longer. For established trees and shrubs you might begin irrigating anytime after midnight and may need to apply water at a slow and steady rate for multiple hours to ensure water infiltrates to the roots at a depth of 2-3 feet.
— Arizona Cooperative Extension/Maintaining Landscapes During Heat and Drought
Some experts recommend watering between 3 am and 6 am. LSU Ag. Center/Dos and don’ts in the garden during droughts.
The Arizona Extension Service recommends prioritizing trees and shrubs when intense heat and drought continue for long periods. We hope that won’t be necessary, but our investment in trees and shrubs and their shade-making contributions would seem to mandate this approach if these conditions continue. Arizona Cooperative Extension/Maintaining Landscapes During Heat and Drought
— “Apply water efficiently. High temperatures mean a high potential for water to evaporate before it ever reaches the roots. Avoid sprinklers and instead use spot watering at the base of the plant, soaker hoses, or drip irrigation systems to provide water efficiently.” Iowa State Ext/Managing the Garden in Extreme Heat.
— “Dealing with dry conditions can be especially hard for vegetable gardeners as many plants need consistent water to continue to produce and some need rain at critical times, such as corn during silking,” Va. Tech News/Heat and dry weather pose problems for landscape plants.
What else?
— “Mulch, mulch, mulch. A 3- to 4-inch layer of mulch can reduce watering needs by as much as 50 percent.” University of California Division of Agriculture and Natural Resources/10 Tips for Vegetable Gardening During a Drought. “But in a severe drought, organic mulches such as woodchips or bark can dry out and take up all the water that is being applied, before the water reaches the soil. The solution is to poke the hose end under the mulch and let the water run gently for a while.” Cornell Coop.Ext/Tomkins County/Watering Guidelines Q & A.
— “Don’t Fertilize. In extreme heat, plant processes slow down. Adding fertilizer promotes growth that the plant cannot support, leading to additional stress.” Iowa State Ext/Managing the Garden in Extreme Heat.
— Do not cause any additional stress to plants. Heavy pruning is not suggested during this time.” LSU Ag. Center/Dos and don’ts in the garden during droughts.
— “Don’t worry if your lawn begins to go summer dormant in the excessive heat. Most lawns can survive 2 to 3 weeks of dormancy, and will green up again as temperatures cool.” Nevada Ext/Tips for Keeping Your Landscape Plants Alive During a Drought.
— “Blossom and fruit drop are common in peppers, squash and cucumbers when high temperatures persist. Most plants will return to typical productions after a heat wave is over.” Oregon State Ext/Heat wave in the garden: How to identify and prevent heat stress in plants.
— “If you cannot take the plant to the shade, then bring the shade to the plant. Utilize shade cloth, screening, or even white sheets to reduce the amount of light hitting the plants and the surrounding soil. Putting up some type of shade cover helps the soil and plants stay a few degrees cooler while reducing the amount of moisture lost.” Iowa State Ext/Managing the Garden in Extreme Heat
— “If using a shade device not typically used for gardening, like a beach or picnic umbrella, consider adding it in the late morning and removing it toward the end of the day so plants get some direct sunlight. Be prepared for plants that are heavily shaded for long periods to “stretch” toward more light.” Oregon State Ext/Heat wave in the garden: How to identify and prevent heat stress in plants.
— “Numerous ornamentals abort or drop buds and flowers after prolonged exposure to high temperatures. This allows the plant to conserve resources for parts of the plant necessary for survival.” Oregon State Ext/Heat wave in the garden: How to identify and prevent heat stress in plants.
We recommend reading all of the articles cited above, especially if you seek a fuller understanding of how drought and excessive heat affect plants. And if, like us, you’re wondering what to expect next, you’ll find longterm outlooks for heat, drought, and precipitation at the National Weather Service’s Climate Prediction Center.
Featured image: “Tired tomatoes“, by risingthermals (cropped, rotated, and colors modified). CC BY-NC 2.0
