I planted a mission fig tree (again) in our back yard. It is 5 feet tall and I put a wire cage around it to protect from gophers. The leaves started turning yellow and dropping off. I then added some iron to the soil but am still getting yellow leaves. Could it be that I over-watered the tree at first or maybe something was wrong with the tree?
Jack Walther, Pioneer
According to UC master gardener Carol Hunter, the yellow-leaf problem may have stemmed from when the tree was planted. Or the gophers may have out-foxed your chicken wire.
When you planted your tree, did you keep the soil at the same level in the ground, as it was in the pot, and not plant the tree too deeply? Planting too deeply can lead to crown rot.
Since gophers can be a problem for fig trees, check to see if the wire cage did protect your tree’s roots. The gophers may have been able to get to the roots by tunneling underground – and under the wire. Check for damage to your tree’s roots. Gophers may be controlled either with traps or toxic baits.
Another possibility is the spider mite. The mite is so small that it resembles a moving dot – about 1/20 of an inch. The damage caused by the mite is yellow-stippled leaves with webbing.
It is important that the correct cause of the leaf drop be determined before beginning treatment. The treatment recommended for spider mites is the regular, forceful spraying of the tree with water with particular attention to the underside of the leaves. Spider mites frequently become a problem after application of insecticides for control of insect pests. Had you recently applied any insecticides in the area?
Additional information on gophers and spider mites can be found at www.ipm.ucdavis.edu.
Proper irrigation scheduling for newly planted trees includes detective work on your part. Periodically verify that the water is penetrating the root zone and that standing water is not a problem. If your soil is heavy clay, avoid keeping the soil overly wet.
This month, you can bring your garden questions to the Farm at the California State Fair. In a special booth, master gardeners will be on duty each day through July 27. To help identify specific pests or plants, bring a sample in a sealed plastic bag. Photos also are helpful.