by B. Rosie Lerner, Extension Consumer Horticulture Specialist
Much of Indiana has found rainfall scarce since last summer, though some areas have received some recent relief. But even with recent rainfall, most areas are well below "normal," especially for so early in the growing season. Gardeners need to take action to encourage plant recovery.
Most plants could benefit by a deep watering every couple of weeks or so, especially if they haven't been watered much in the past six months. But some plants will need even closer attention. Newly planted trees and shrubs 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. Broad-leaved evergreens, such as rhododendron and holly, 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, mulch can be helpful, not only in conserving soil moisture but also in keeping weed growth to a minimum. When water is scarce, you don't want to share any bit of it with unwanted weed growth. Use a 2-3-inch layer of coarse material, such as chipped or shredded bark.
Many woody plants may continue to show effects of the drought through spring and beyond. Some branches may die back during the winter and fail to leaf out this 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.
Fertilizer can help injured plants recover by encouraging new growth, but it's best to go easy. Too much fertilizer may actually burn young growing roots, causing further damage. It's best to err on the light side and then apply additional fertilizer in late fall.
Flower and vegetable gardens may need more attention to watering than is typical for most spring seasons. Young transplants and seedlings are particularly susceptible to drought injury; they don't have much in reserve to draw on for recovery. You may need to water more frequently than once a week for very young plants, especially during warm, breezy, sunny conditions. Again, applying mulch will help conserve soil moisture around garden plants and minimize competition from weeds.
Site last updated: 10 April 2006
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