Keeping Your Plants Alive Through Dry Fall and Winter
November 23rd, 2016 by Anna Bell King
ADVICE from our Garden Manager: Keeping your plants alive through this dry fall and into winter
Dry summers are not that unusual in the South. But, this year’s dry spell has been exceptional. Of particular concern this year is that the dry spell is continuing well into autumn, putting plants in poor condition to get through the winter months when water will be unavailable due to frozen soil. Newly planted trees, shrubs, and perennial flowers will be at most risk from winter injury caused by desiccation. Established plants may tolerate drought better, but still will be more susceptible to winter injury if they are in a stressed condition.
Woody plants, especially evergreens, are susceptible to drying out over winter, broad-leaved evergreens (camellias and hollies) even more so. The aboveground parts such as twigs and evergreen leaves are very much alive through the winter and are continuously losing water through a process called transpiration. Once the ground is frozen, the plant’s roots are not able to take up water to replace what they lost through their tops. The result is drying leaves, buds, and twigs. While we love sunny days in winter, this will cause more water to be lost. But, it’s the harsh, windy conditions of winter that can cause the most water loss to the leaves, further aggravating the situation. Broad-leaved evergreens are particularly vulnerable, since they have a greater leaf surface from which to lose water, unlike pines or other conifers. Making sure the plants have a sufficient supply of soil moisture before the ground freezes will help your trees and shrubs come through the cold healthier and able to better fight the bitter winter battle.
What you should do:
In dry fall seasons, it is important to water thoroughly every 7-10 days. While woody plants do have some roots that grow very deep, they also have feeder roots. These are the very small roots responsible for the bulk of water uptake that occurs in the top 12-18 inches of soil. Most of these feeder roots are concentrated below the dripline of the plant and beyond, not up close to the trunk. Allow water to thoroughly soak the target soil area by applying at a slow enough rate to allow penetration; avoid run-off as much as possible. Plus, use mulch wherever possible to conserve moisture.