Suckers Can Be Cut Off, Discouraged
QUESTION: A semi-dwarf plum tree is planted in a 4-foot raised planter at the back of my yard. It has been sending up suckers at its base and now down below in the grass area. Can anything be done to prevent or control this?
--J.B., Lake Forest
ANSWER: Plums of all kinds, edible and ornamental, are notorious for suckering. So are olives, mayten trees, Chinese and other elms, willows and a few others, but most are usually under some kind of stress if they start shooting up suckers. Perhaps the roots, which are close to the surface, have been damaged. Something happened to start the suckering.
You can cut off the suckers on the roots or trunk, at what is called the “collar.”
This is where pruning cuts should be made on trees, and it is not flush with the root, branch or trunk--as is often suggested--but a bit back from it. Look closely and you will see a little collar-like swelling on the bark where the sucker is attached. If you make the cut here, it will heal quickly and surely. Cover the wound with tree paint or wound dressing (sold at nurseries), and the suckering may stop.
There is also a chemical approach. Monterey Lawn & Garden products makes a product called Sucker-Stopper RTU, a plant-growth regulator named NAA, which comes in spray bottles. After you prune the suckers off, spray the cuts with Sucker-Stopper, and they shouldn’t return for a year, according to the manufacturer. Or spray the trunk or roots where suckers keep occurring, before new ones sprout.
It can also be used on apples, citrus, olives and woody ornamentals, but do not spray it on flower buds or leaves, and be sure to read and follow label directions.
Liquidambar’s Roots May Have Been Cut
Q: About 12 years ago, we purchased a beautifully shaped, healthy-looking liquidambar tree. This year, I noticed that a lot of leaves were yellow-green on one side of the tree. It is still well-shaped except that the very top branches did not develop leaves. What can be done to help it grow leaves on top? Is there such as thing as a tree doctor?
--M.S., Fullerton
A: This is a job for a consulting or a certified arborist (they’re listed in the Yellow Pages). These “tree doctors” can look at the tree and its surroundings and tell you what’s actually wrong. When I mentioned this to consulting arborist Bob Hansen, he said he had just seen a similar problem.
This liquidambar was also doing poorly on only one side, like yours, and wasn’t leafing out on top because someone had dug a trench for a sprinkler line on one side of the tree, severing some of the roots.
He also told me that awhile back, he went to a garden where big liquidambars in a row were dying; he found a trench for electrical lighting dug along one side. All the roots on that side of the row had been cut.
Ironically, the trench was being dug for lights that would illumine the liquidambars, but the whole row died just after the lights were installed.
Hansen says that whenever he gets the chance--before the deed is done--he tells electrical contractors and plumbers to think of roots as high-voltage lines or gas lines.
“You wouldn’t cut through a 2-inch gas line, would you?” he asks them. “So don’t cut through roots. Tunnel under them.”
Plumerias Prefer Full Sun, Grow Well in Pots
Q: Do plumerias grow in full sun? I live in the Pomona Valley.
--S.M., Claremont
A: Yes. To bloom well, plumerias must grow in at least a half-day of sun, and a full day is preferable. According to wholesale grower Marilynn Cohen, who grows 50 types of Hawaiian hybrids, they do very well in the Pomona and San Gabriel valleys (San Gabriel Nursery is one of her biggest customers), as well as in the L.A. Basin and Orange County.
Only in Phoenix or Palm Springs do they need a little afternoon protection from the sun. She adds that in shady areas, they may get spider mites and thrips.
Plumerias need a warm, sunny spot, against a south or west-facing wall for instance, or on a pool deck, where there is reflected heat. In your area, however, they may need protection from the occasional frost.
They are usually grown in pots because they need a fast-draining, porous soil and because they do not have a big root system. In containers, they can be moved to a safe spot if frost is predicted, and the soil can be kept dry in winter when they are dormant (resume watering when they begin to leaf out in spring).
They will grow in the ground but may rot in wet winter soils, and in the ground, protecting them from frost becomes a much bigger job.
Deer and Squirrels Are Here to Stay--and Eat
Q: Any tips to keep deer from eating the tops of Lily of the Nile and Iceland poppies?
--P.H., Laguna Beach
A: We’ve received many questions concerning deer and squirrels and what a nuisance they are, but neither of these animals can be stopped, unless you build some kind of a cage to keep them out. Deer can jump most ordinary fences, and squirrels can climb just about anything.
There may be things--lion dung or other repellents for deer, or flashing metallic tape for squirrels--that work for a day or two, but nothing works for long.
There are lists of plants that deer don’t like (which are always qualified with phrases like “unless they’re really hungry”; the Sunset Western Garden Book includes one), and there is an entire book on trying to keep squirrels out of bird feeders (“Squirrel Wars: Adventures in Bird Feeding,” by Ary Renaud), but it concludes that nothing really works.
Questions should be sent to “Garden Q&A;” in care of the Real Estate section, Los Angeles Times, Times Mirror Square, Los Angeles, CA 90053. Please include your address and telephone number. Questions cannot be answered individually.
