ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, December 22, 1996 TAG: 9612240011
SECTION: HOMES PAGE: 2 EDITION: METRO
COLUMN: Dear John
SOURCE: JOHN ARBOGAST
Of course they don't bother us in the winter, but it's never too early to eliminate breeding places so mosquitoes won't bug us in the summer.
There just isn't any product designed to be sprayed on the ground or trees, shrubs or fallen leaves to eliminate mosquitoes once they have hatched. Getting rid of breeding sites, which could be anywhere water stands in a pool, is the best bet.
The blood-sucking pests' eggs, pupae and larvae need still water to develop in, so most adult mosquitoes remain close to the lake, pond or clogged gutter that they lived in as larvae. However, they will travel a mile or more from their breeding spot to find a meal.
Fungus gnats can be bothersome indoor insects at this time of year, particularly where there is potting soil that stays wet for long periods because of cooler rooms or overwatering.
Don't be misled by the word fungus in the name. These insects are actually flies whose adult stage can be seen flying around windows and lights. The larvae of fungus gnats lives in moist soil where their eggs were laid and where the young feed on decaying organic matter.
Control of fungus gnats indoors is relatively simple. Adult gnats are attracted to moist, organically rich soil. So, an excellent control to stop their breeding and eliminate the continued presence of adult fungus gnats is to examine all indoor plants for overwatered soil. Allowing the soil to dry for several days shouldn't stress your plants but will cause the larvae in the top layer of soil to die and will remove the necessary egg-laying environment needed by adult fungus gnats.
Q: I have several questions concerning the use of mulch around the trunks of landscape trees. What is the best type of mulch for this? What is the optimum depth and area of mulch around tree trunks? Is there any danger of having too much mulch? R.C.R., Roanoke
A: Any of the various shredded bark or wood mulches are excellent for the landscape. Also good but not as commonly used in this area is pine-needle mulch, which might be referred to as pine straw. Pine-needle mulch decomposes slowly and resists compaction but might be considered very flammable.
For trees and shrubs, spread organic mulch evenly to a depth of 2 inches to no-more-than 3 inches. For plants in beds, mulch the entire bed. For those in a lawn, especially young plants, mulch a wide ring around each plant extending out to the branch dripline or a distance of 3 feet to 6 feet out from the trunk.
There is a very real danger of having too much mulch around a trunk. More than an inch depth of mulch piled against tree trunks could cause damage to the tree's bark because of constant moisture from the mulch. Excessive mulch against the trunk could serve as a home for mice, which chew on bark this time of year. Mulch depths greater than 4 inches can impede the exchange of gases between the soil and the air above, causing roots to slowly die from what we might call stagnant soil or suffocation.
The only potential danger from mulching too great of an area might be the increased fire risk created when the top portion of the mulch gets dry.
Send short questions about your lawn, garden, plants or insects to Dear John, c/o The Roanoke Times, P.O. Box 2491, Roanoke, Va. 24010-2491. We need your mail, but this column can't reply to all letters. Those of wide appeal will be answered during the weeks that the subject is timely. Personal replies cannot be given.
Please don't send stamps, stamped envelopes, samples, or pictures.
Gardener's checklist
Job for late December:
To prolong blooms, protect poinsettias from hot or cold drafts as well as chilly temperatures; provide bright, natural light and water thoroughly but only when the potting soil feels just barely damp.
John Arbogast is the agricultural and natural resources extension agent for Roanoke.
LENGTH: Medium: 76 linesby CNB