Q. While spraying a weedy patch with Roundup, I inadvertently exposed some evergreens to the herbicide, and now quite a few of them have brown needles. Can I restore these plants?
A. Roundup is a non-selective herbicide that can seriously damage or kill most plant material it contacts. It is also capable of interfering with a plant's ability to generate new growth. Once evergreen needles turn brown, they will not turn green again. Check to determine if just the needles are brown or if entire woody branches have died. Starting at the tips of the damaged branches, work backward, down the branch, carefully pruning out brown, dry wood until you hit green pliable wood. After pruning out all the dead wood, assess the overall damage and the shrub's potential. Sometimes healthy branches will produce enough new green growth to mask bare spots. A few evergreens, such as yews, can be pruned down severely to 18 to 24 inches and will generate new growth on these low branches. It normally takes three to five years before they begin to look acceptable. Most gardeners acknowledge that if more than half a woody plant has been damaged, it will rarely recover enough in a short time period to occupy a prime place in your landscape. Struggling plants are also prime targets for disease and insect attacks. Continue to water your evergreens regularly. Early next spring, spread a slow-release, balanced fertilizer around the root zone of the shrubs and water it in well. Make your decision once the new growth has filled in.