QUESTION: My neighbor has a very large yucca tree that is pushing against my block wall. The wall is now cracked and I'm afraid it will fall. The neighbor is not reluctant to remove the plant. Do you have any suggestions on the easiest method?
ANSWER: I watched a neighbor struggle with a huge yucca only to give up, leaving the thick base of the trunk in the ground. If only they'd known that they were almost there. Although the top is ponderous and heavy, the base goes only about eight inches underground and there are no large roots underneath, despite appearances. Another foot and it would have been gone.
Cutting down a yucca is slow work because the wood is wet and heavy. Arborists Don Case of Fullerton and Bob Hansen of Santa Monica suggested cutting off small pieces at a time and, when you reach the base, digging to undermine one corner, then chipping off manageable chunks with a Pulaski (an ax-handled digging and cutting tool). An alternative: Cut it to within six inches of the ground and call in a root grinder (most tree services have them).
Dahlias Take Center Stage at March Show
Q: I enjoy growing dinner plate-size dahlias, most of them ordered through the mail. Can you tell me about other dahlia catalogs?
A: Barbara Barton's "Gardening by Mail" (Houghton Mifflin, $18.95) lists just about every mail-order plant and garden catalog in the U.S. and Canada, including 21 dahlia growers. This is also the time of year nurseries carry the tubers, and the South Coast Dahlia Society will have a sale of tubers at 2 p.m. March 17 at the South Coast Botanic Garden on Crenshaw Boulevard on the Palos Verdes Peninsula. The tubers for sale will be kinds that do well in Southern California, and there will also be a talk on how to plant them. The society's flower show is held on the second weekend of August.
Members also suggested these mail order sources: Almand Dahlia Gardens, 2541 W. Ave. 133rd, San Leandro, CA 94577, (510) 357-2687; Alpen Gardens, 173 Lawrence Lane, Kalispell, MT 59901, (406) 257-2540; and Connell's Dahlias, 10616 Waller Road East, Tacoma, WA 98446, (800) 673-5139. To learn more about the South Coast Dahlia Society, call Dick Kohlschreiber at (310) 833-6823.
2 Fungi, Bug Attack St. Augustine Lawns
Q: My St. Augustine grass is getting destroyed by something. It seems to die in great patches from below. I dug for cutworms and could not find any, but the roots seem dead. What's killing it?
--H.F., Silver Lake
A: St. Augustine is one of the least trouble-prone lawn grasses, even in the shade, which it tolerates better than any other grass. Problems are rare, unless the lawn is getting old (10 years or more). John Rector, the agronomist at Pacific Sod, says your problem may be one of two fungus diseases or perhaps the chinch bug.
If the damage is noticeable in fall and winter, and the diseased areas first turn an "almost fluorescent yellow" before the grass turns tan and dies, it is probably a new disease called Take All Patch. It moves fast through the lawn and attacks the roots, turns them almost black and severs them from the ground. There is unfortunately no control other than to try and keep the lawn healthy.
Brown Patch is another disease seen May through September that kills grass in circles larger than dinner plates. It is easily controlled with any of the lawn fungicides and will be listed on the labels of appropriate products.
Chinch bug is also easily controlled with a lawn pesticide (again, the bug will be listed on the label). If you want to check to see if this tiny bug is present, simply put a white piece of paper on the grass and brush it. These tiny bugs will jump and can be seen landing on the paper. They feed on the foliage and can kill large areas.
Before applying any of these controls, water the lawn thoroughly and be sure of the problem. It could also be cultural. If the lawn is watered often but not very deeply, the poorly rooted St. Augustine will die out in patches that become too dry and water repellent. Too much thatch can also cause this, and the remedy is to have the lawn renovated with a vertical mower. Lawn services can do this, and experienced companies may be able to help pin down your problem.