Issue: October 7, 2000

• Black, damaged bark on mulberry
• African violet

Black, damaged bark on mulberry

I have a mulberry tree with a problem. I have noticed the tree looks like it is burned. However, if you wipe the tree, you do not get a black ash like charcoal on your hands. The affected areas of the tree have already begun dying off. The bark is pulling up off the tree. What is the problem and is it curable?

There are several things which could be causing your problem, some of which I probably haven't confronted in New Mexico. According to Bob Cain, NMSU Extension Forest Entomologist, the blackening of the bark could be due to sooty mold, a fungus that grows on the honeydew excreted by aphids, white flies, or other sucking insects which have been feeding on leaves in the tree. However, sooty mold should not cause the bark to die and peel from the wood.

There may be sun scald damage to the tree occurring in the winter caused by the bark heating too much in the day when there are no leaves to shade the trunk. It may also be possible that there is a vascular disease active in the trunk of the tree causing the problem. Another possibility is that there are borers infesting the trunk. Borers are quick to attack trees damaged by other factors.

It would be a good idea to contact your local Cooperative Extension Service office, a free service of New Mexico State University. The Extension Agent can often diagnose such problems and give an immediate recommendation. There is an Extension Service office in each county, so there is one near you. There are also volunteer Master Gardeners associated with the Cooperative Extension Service who can be of assistance.

African violet

How long does the African violet last?

I am not sure if you are asking me how long an African violet flower lasts, or how long the plant lasts.

An individual flower may persist on the plant for several weeks and, in some cases, a month. However, the plant remains in bloom, producing many flowers for months at a time, sometimes years.

The plant itself, if properly cared for, can last many years. It will require repotting periodically. At the time that you repot it, the long stem which develops below the leaves should be buried deeper than before. New roots will form along the stem.

It is important to take good care of the plant to maximize its life span. Don't let it experience cold temperatures. It cannot survive freezing temperatures and can be injured by low temperatures above freezing. The African violet plant must not be allowed to dry too severely, but a little drying is much better than too much water. Especially harmful to the African violet is irregular watering. Don't alternate between very dry and soggy soil conditions.

Of course, when the plant gets old or is not doing well, it is possible to propagate it from a leaf cutting and produce a new plant exactly like the old plant. Then, although the new plant is not exactly the same plant, it has all the characteristics of the original plant. However, if the plant is patented, it is not legal to vegetatively propagate it in this manner.

Send your gardening questions to Yard and Garden, ATTN: Dr. Curtis Smith NMSU Cooperative Extension Service 9301 Indian School Road, NE, Suite 112 Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.

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