Issue: August 27, 1997
Transplanted trees sick
Question:In May of this year I had 3 sugar maple trees (20-25 ft) transplanted into my yard. The leaves came out just fine at first; however, now they appear to be yellowing (they have a greenish yellow hue) and some are even browning and falling. I am watering them frequently as we have had little rain since May, but still they are not greening back up. Is there any nutrient/fertilizer I could use. Also I have noticed some brown spots on most of the leaves...is this some kind of disease? Any help you can suggest would be appreciated.
Answer:When large trees are transplanted, much of their root system (up to 90 percent) is left behind. Until a new root system can be generated, the plants will suffer from desiccation stress and transplant shock. The process of establishing a new, adequate, root system can sometimes take several years and is dependent upon the size of the transplanted tree as well as soil moisture. I suspect you are seeing the effects of transplant shock as the limited root system cannot provide sufficient water and nutrients to the leaves.
Fertilization during the establishment period is not necessary in most soils. There should be sufficient nutrients in all but the sandiest soils for the first year or two of growth. Excessive fertilization, which stimulates growth of stems and leaves, prolongs the time in which the root system is inadequate to support the top. A little fertilization after the second year will help, but be careful not to apply too much nitrogen.
Pruning to "balance" the top with the roots is also not advised. Just prune those parts which weaken and die. Too much pruning will reduce the number of leaves which are important in providing food necessary for root development.
Since there are diseases and insects which could also contribute to the symptoms you have described, it would be wise to consult with local horticulturists who are familiar with your local conditions and horticultural problems. Check with local nurseries, the Cooperative Extension Service, or Master Gardeners.
Weeping fig dropping leaves
Question:My weeping fig has practically dropped all its leaves. I moved it to a sunnier corner in my apartment but it still drops leaves. I just got it 2 weeks ago. I water it once a week with enough water I think and a few drops of plant food. Help! I don't know what else to do.
Answer:Weeping fig trees have a reputation for dropping their leaves when they are moved. The slightest change in environment, due to moving, the first few weeks after the furnace is used in the autumn, change in sun angle which alters the light received as seasons change - any of these can cause leaf drop.
You stated that you had received the plant two weeks earlier. That suggests that the move from the nursery to your home, or from the grower to the nursery, could be the cause of the leaf drop.
Other things could cause problems as well. Too much water, too little water, or just the change in watering schedule can cause leaf drop. The worst of these is too much water which promotes root damaging fungi.
You should also look for insects on the plant. Mealy bugs, white cottony looking insects, aphids, or scale insects could be the culprits. The aphids and scale signal their presence by creating a honey-like excretion which coats the leaves and perhaps the stems. If you observe this sticky material, identify which insect is the problem, then apply an appropriate control measure. This may involve spraying with insecticidal soap or treatment with a cotton swab dipped in insecticidal soap or oil. These products are safe for indoor use.You should be able to get some assistance in identifying the problem by contacting your local Cooperative Extension Service, Master Gardeners if that volunteer program is active in your community, or by taking a sample to some local nurseries.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.
Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!
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