Preparing your garden for summer heat
Saturday, July 7, 2018
Much like people, plants are going to respond to heat stress differently. Some will tolerate it very well, while others will show sharp signs of decline. Unlike people, plants don’t have the luxury of going into the air conditioning for the hottest parts of the day. It’s important to note that most plants will not exhibit problems after one day of excessive heat, however problems may arise after one week or more of extremely high temperatures.
Research shows that when daytime temperatures average greater than 90 degrees and nighttime temperatures average greater than 70 degrees, pollination of flowers may stop. This is due to flowers terminating, poor pollen production or sterile pollen production. If your tomatoes, peppers or squash have stopped setting flowers and fruit the past week, this is most likely why. But do not worry. Flower production will pick up again when the extreme temperatures break.
The incredibly harsh winter we experienced this season may cause plants to struggle during excessively hot days. Freezing temperatures of the spring may have damaged cambium tissue in plants. This damage might not have been evident immediately if the plant still had the capacity to meet its minimal water and nutrient transportation needs. Winter-damaged stems may be unable to move sufficient water to the foliage during excessively hot days because the demand for water is much greater. A proper and consistent irrigation schedule helps to alleviate this issue. During periods of excessive heat and drought, an established plant should receive 1 inch of water per week, while newly planted plants should receive three-fourths inch of water every three to four days.
Plants in an urban area may suffer from extreme heat more than plants in a garden or field setting. The most common urban areas where plants suffer from heat stress are parking lot islands and sidewalk plants. Radiant heat has potential to damage plants by reflecting heat from impermeable surfaces, such as pavement, into plants. Little can be done if a plant is established in one of these areas, so proper planning should be done at planting to ensure the right plant will be given proper growing conditions.
When it comes to problems related to heat, just remember, we cannot change the weather, but we can take some preventive measures to alleviate heat stress of plants. For more information on how plants respond to excessive heat, contact the Pitt County Extension Master Gardeners at 902-1705.
Are you interested in increasing your knowledge in horticulture and volunteering in the community? Then the Pitt County Extension Master Gardener Class may be for you. The next class in Pitt County will be held from 3-6 p.m. Fridays and Tuesdays from Aug. 17-Sept. 21. The registration deadline is July 31. Call 902-1700 for more information.
Eric Derstine is the horticulture agent with the North Carolina Cooperative Extension Service-Pitt County. Contact him at email@example.com.