Keep Your Evergreens Green
Treat yellow-green leaves with compost or fertilizer
If your hollies are heavily loaded with berries this fall, most likely the foliage will turn yellow-green, downgrading the contrast with the red berries. It takes a lot of energy and nutrients for plants to produce fruit. This is especially true if the branches are heavily laden with large clusters. Heavy-fruiting hollies generally appear chlorotic. This problem can be corrected by applying a nitrogen-rich mulch such as lobster compost, chicken manure compost or lawn fertilizer between the trunk of the plant and the drip line. For hollies, this treatment should be applied now and the trees irrigated weekly until early December.
If the plants have had pale green foliage all summer long, they most likely are deficient in magnesium. Without soil test results to confirm this diagnosis, I often recommend spreading one-third cup of epsom salts per 10 square feet. Magnesium deficiency is not an uncommon problem with hollies laden with bright red berries.
Boxwoods that appear yellow-green in the fall often experience excessive leaf drop due to nitrogen deficiency. If the winter is especially severe, many boxwoods will also exhibit bronzing. Both of these symptoms can be prevented by fertilizing the plants soon after the first frost. Applying one-half cup of a lawn fertilizer for every three feet in height or spread is generally adequate. Make certain that you use only a lawn fertilizer that does not contain weed killers. Apply the fertilizer uniformly beneath the drip line of the branches. Since boxwoods are very shallow-rooted, they will quickly respond to the treatment.
Azalea are also susceptible to early fall discoloration and loss of leaves. Roots are unable to provide sufficient nitrogen for flower-bud development. As a result, nitrogen from the lower leaves migrates upward to the developing flower bud at the tip of the branches. Chlorosis of the bottom leaves is very common on white-flowering azaleas because they flower in abundance. This problem can be solved by mulching them with either Maine Lobster Compost, compost made from crab waste or ammonium sulfate fertilizer. If using ammonium sulfate fertilizer, apply only one tablespoon per two feet of height or spread of the azalea plants. Apply the ammonium sulfate mostly under the drip line of the branches.
What’s Killing My Spruce?
Q I have a 50-year-old spruce tree that is dying from the bottom up. What would cause this (just old age?) and is there anything that can be done to save it? Thanks for your advice. I love Bay Weekly.
–Mary Jane Gibson, Lothian
A It is not old age because spruce trees can live 100 years or more. Which spruce is it — Norway, white, black, red, Colorado, Engelmann, Siberian, etc.? Look at the ground under the branches for holes about the size of a silver dollar. If you see such holes, it is possible that pine mice are girdling the roots. If so, you have to kill the pine mice with poison bait for mice (available at the hardware store). If the trunk is bleeding sap, then the tree is infested with cankers. Or the tree may be suffering from weed killers if you have used them on your lawn.
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