Editor’s note: Kelly R. Jackson takes questions called into his phone recently at the Christian County Extension Office and answers them in the Garden Corner column.
Question. All this rain is causing my lawn to grow fast. How high should I mow my tall fescue?
Answer. Mowing at the right height can have a big impact on the overall health of your turf and future weed problems. Following recommendations for mowing height and frequency will make your lawn-care duties easier and result in a more attractive yard.
If your mower has a fixed, all-year height, set it at 2 1/2 inches for cool season grasses. However, if you can easily vary the height, set it at 1 1/2 to 2 inches for the first several times you mow in the spring. The shorter mowing height will help remove a lot of the winter-burned, brown leaves. Exposing more dark green growth will transform your lawn into the most uniform, attractive one in the neighborhood. Move the height up to 2 1/2 inches after you mow the grass several times.
To protect your grass from summer heat and drought injury, when summer arrives raise the mower height to three or 3 1/2 inches. Mowing grass a greater height can also impact weed growth. As the leaf blades are left longer they overlap more and shade the soil surface reducing the amount of sunlight penetrating to the ground and increasing competition for emerging weed seeds. However, remember that extra high grass, especially tall fescue, tends to fall over and mat down during hot summer weather causing increased summer disease problems.
Once you get the mowing under way, how often should the lawn be mowed? Generally speaking, mow often enough to remove no more than one-third to one-half of the grass height. If your mower is set for 2 inches, mow again when grass height reaches approximately 3 inches. Be sure not to scalp the lawn by mowing off most of the green leaves.
For tall fescue lawns, a rule of thumb is to mow at five-day intervals during the spring, and at seven-day intervals the rest of the year. That interval can probably be expanded during hot, dry weather.
Q. Does mulch attract termites?
A. A common concern from homeowners is if the use of mulch attracts termites. The bottom line is that mulch applied correctly will not likely cause termite problems. However, termites are attracted to the moisture-retaining properties of mulch and the insulation it affords against temperature extremes. An excessive depth of mulch can compound termite problems. The mulch itself is of poor nutritional quality to termites and a non-preferred source of food. Since the moisture retaining properties of mulch are more of an attractant than the wood itself, it makes little difference what type of mulch is used (cypress, pine bark, eucalyptus, etc.). Contrary to popular belief, crushed stone or pea gravel are comparable to wood mulch in terms of attraction, since they also retain moisture in the underlying soil. “Treated mulches” are of questionable benefit, and since moisture is the big draw, are not preferred over conventional mulches. Where mulch is used, it should be applied sparingly (2-3 inches is usually adequate), and should never be allowed to contact wood siding or framing of doors or windows.
Kelly R. Jackson is the Christian CountyExtension Agent for horticulture. He can be reached at 270-886-6328 or visit Christian County Horticulture online at www.christiancountyextension.com.