Yard and Garden News
By B. Rosie Lerner
Extension Consumer Horticulture Specialist
Much of Indiana found rainfall scarce throughout the summer, and even into the fall, so gardeners need to make sure their landscape plants have an adequate supply of moisture before winter arrives.
Most plants could benefit by a deep watering every couple of weeks or so, right up until the ground freezes. But some plants will need even closer attention. Newly planted trees and shrubs may have limited root systems and may need a weekly watering. Evergreen plants are particularly subject to winter drying since their leaves continue to lose moisture all winter long. Once the ground is frozen, little water is taken up by the roots to replace that which is lost through the leaves. Broad-leaved evergreens, such as rhododendrons and hollies, have more leaf surface exposed and are most subject to injury.
It's best to water deeply occasionally, rather than frequent shallow sprinkling. Apply 1 to 1.5 inches of water around the root zone of the plant. Be aware that the roots may spread farther than you think. The size of the root system varies, depending on the plant species, its age and the soil conditions. In general, the roots extend quite a distance beyond the drip line of the tree or shrub.
For newly established plantings and shallow-rooted plants, a winter mulch can be helpful not only in conserving soil moisture, but also in keeping plants in the ground. These plants can be heaved out of the ground if the soil tends to alternate frequently between freezing and thawing. Apply winter mulch after the plants have become fully dormant, generally by late November or perhaps December. Use a 3- to 4-inch layer of coarse material such as straw, chopped leaves or shredded bark.
Many woody plants may continue to show effects of the drought next spring and beyond. Some branches may die back during the winter and fail to leaf out next year. In the case of twig injury, rather than death, the stems may leaf out, but die back later in spring or summer as that branch becomes stressed. Prune out any dead or damaged branches by cutting back to their point of origin.
If plants appear to be dead, cut away the outer bark and look for green tissue underneath, an indication that there is still hope for regrowth. Also, check for the presence of buds, which, likewise, should be green in color when cut open. Dead plant twigs generally will break clean when bent; live twigs should still be somewhat flexible.
Last updated: 10 April 2006
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