Tall Fescue Lawn Care in Virginia

Tall fescue survives a Northern Virginia summer better than any other cool season grass, so it makes up most lawns here. Its roots run far deeper than Kentucky bluegrass, so it pulls moisture from below when the top few inches of clay bake dry. It also takes more shade than most turf, which matters on wooded lots around Reston.

We're in the transition zone, which is too hot for the bluegrass lawns you see in the upper Midwest and too cold for zoysia or bermuda to look like anything from October through May.

Tall fescue doesn't spread, so it has to be overseeded every year. Each plant grows straight up from its own crown with no runners, so when one dies in August nothing replaces it and a weed fills the gap by spring.

The fix is one job a year, and that's to aerate and overseed every fall. Our blend uses Barenbrug Blue Tag certified tall fescue, an improved turf type selected for disease resistance and summer survival in the transition zone. Aeration and overseeding with us is $279 flat for lots up to a quarter acre.

Mow tall fescue at three and a half inches most of the year, and raise it to four inches in July and August. Taller blades shade the soil, hold moisture and block the light crabgrass seed needs. Never take more than a third of the blade at once, and keep it sharp, since a dull mower shreds fescue and causes grass that looks brown in summer.

Tall fescue needs about an inch of water a week, in one or two long soakings instead of a little every day. Deep watering drives roots into the clay where summer moisture sits, while daily sprinkling keeps them in the top inch. Water early and finish by about 9 a.m., since grass left wet overnight invites fungal disease.

Brown patch is the main disease threat to fescue in Virginia, and it arrives with the humid stretches from late June through August. Look for roughly circular tan patches, worst in shade, low spots and dead air. Up close, blades show tan lesions with dark borders, unlike the uniform straw color of drought.

It hits lush, heavily fed turf hardest, which is why we don't push fertilizer into a Virginia June. Mowing high, watering at dawn and opening up airflow prevent most of it, and a fungicide program covers lawns that get it yearly. Thinned patches still need fall seed.

Turf type tall fescue is the improved grass with finer blades that goes into modern lawn seed, and K-31 is the old pasture variety builders used for decades because it was cheap. Coarse clumps of wide, lighter green blades standing above the rest of the lawn are the giveaway.

K-31 never blends in with the rest of the lawn. Overseeding with turf type cultivars dilutes it as the old plants die out, although killing the worst areas and reseeding is faster. Time either one with the aeration and overseeding window.