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06-01-06

Question and Answer

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Q. Last summer I was troubled by so much green moss on some of my flower beds. I am sure I will have the moss again this year because much of it has lived over this winter. What can I do to get rid of it? Does the moss affect the flowers and plants in a negative way?

A. True moss tends to grow in areas of moist shade, where there is little competition from other plants. It can grow in areas of the lawn that are sparse, due to shade, or in flower beds, pavement, even on buildings. You can rake the moss off and allow it to dry out, or there are chemicals that can be used to spot kill the existing moss. However, the moss will soon grow back if the environment is still the same. Some products, such as copper sulfate and iron sulfate, may leave a stain, and herbicidal soaps can leave a bleached appearance (Moss-Aside, Safer's Moss and Algae Killer, Monterey Herbicidal Soap, etc.). Be sure to read and follow all label directions.

Q. Several years ago, a friend gave me some seeds to small mangoes, which are round and are green and turn red. Do you know where these plants can be purchased? I have looked in some seed catalogs and can't find them.

A. Sounds like a cherry pepper, which can be hot, mild or sweet, depending on the cultivar. Of course, you can always check with your local garden centers to see what they carry, but you may need to buy seed from a mail-order company. Here's a list of cultivars and their sources.

Q. I'm a recent transplant from New York. My problem is the everbearing red raspberry in my backyard. The first year the yield was good. The second year, they contracted some sort of blister and are dying. The plants looked healthy in the spring and as they matured toward blossoms. Then, the berries withered, turned black and died. The stems and leaves turned a silver-brown color. We tried several types of spray, powder and fertilizer recommended by a hardware/garden center, and nothing worked. If I can't stop it this year, there will be no more plants. That's how serious it is. Can you help me?

A. It's difficult to say for certain without seeing the plants but my primary suspect is a fungal disease, most likely spur blight or anthracnose (anthracnose is more likely on black or purple raspberries but some red raspberries are also susceptible). Both diseases infect young raspberry canes and leaves. The lesions on the canes continue to enlarge and can eventually girdle the stem before the crop matures, causing the berries to dry up.

Rainy weather and overcrowded plantings favor disease development. The fungus overwinters on either healthy or dead raspberry canes, so pruning out infected canes and removal of fruiting canes after harvest will help reduce infection in subsequent years. For varieties that have a persistent problem with the disease each year, applying a delayed dormant spray of lime-sulfur when leaf buds are just showing about one-eighth inch green can provide some protection.

Since this is an everbearing type raspberry, you might consider sacrificing the summer crop and harvesting just the fall crop. This would reduce overcrowding and the overwintering sites for the fungus. Cut or mow all the canes to ground level in the spring before growth starts. When new canes emerge, thin to correct spacing and keep the row 12 to 18 inches wide to promote good air circulation.

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