How do I fix a lawn that is mostly weeds and bare spots?

A lawn that is mostly weeds and bare soil is past patching. Spraying a few weeds and scattering seed in the gaps tends to leave you with the same thin lawn a year later. The fix that works is a renovation: find out why the grass failed, clear what is growing there now, correct the soil, and reseed the whole area at the right time of year.

Start with why the grass failed

If you skip this, the new lawn usually goes the same way as the old one. The usual suspects are neglect, mowing heights that were too low, too much or too little rain, a nutrient deficiency, the wrong pH, poor drainage, compaction, or a grass that was a poor choice for the site.^[1] Walk the yard and note where the worst areas are: under trees, along a path everyone cuts across, in a low spot that stays wet, or on a bump the mower scalps.

Virginia Tech calls a soil test the first step toward correcting a problem lawn,^[1] and many of Virginia's soils are very acid and probably need lime.^[1] When we checked on October 27, 2026, the Virginia Tech Soil Testing Lab charged $10.00 per sample for its routine test for Virginia residents,^[8] and the report comes with a fertilizer and lime recommendation with the results.^[8] Lime takes time to work, so sample now even if you seed in a few weeks.

Our guide to why a lawn has bare patches goes through the causes one by one, with what to look for.

Pick the right season and grass

Most Virginia lawns are cool-season grasses such as tall fescue and Kentucky bluegrass, and late summer to mid-fall is the best time to establish them;^[1] early to mid spring is the other good window.^[6] Seeding in fall also keeps summer annual weeds such as crabgrass from choking out the seedlings.^[2]

Tall fescue is one of the best-adapted lawn grasses across Virginia,^[4] and it is the default for a sunny yard in most of the state. Shade, heavy traffic and the warmer southeast change the choice, and Virginia Tech's turfgrass guide^[4] compares the options. If you want bermudagrass or zoysiagrass, the calendar flips: warm-season grasses are seeded from mid-spring through early summer,^[6] and hybrid bermudagrass can only be established from sprigs, plugs or sod.^[4]

Clear out the weeds

When most of the area is weeds, a complete renovation means killing the existing cover first. Virginia Tech's pest management guide suggests a nonselective herbicide such as glyphosate, applied at least a week before seeding, and longer is better. Where bermudagrass or other hard-to-kill perennials are mixed in, allow four weeks or more for a repeat treatment of the plants that escaped.^[2] Glyphosate kills any vegetation it touches, including desirable grasses,^[7] so spray on a calm day, keep it off beds and the neighbor's lawn, and follow the label.

Check what has already gone on the lawn this year. Most herbicides require a 30-day wait before turfgrass can be seeded, and seeding may be restricted for 60 to 120 days after a preemergence crabgrass preventer.^[2] A late-summer preventer for annual bluegrass is a trap for fall seeding too: seeding has to be delayed two to four months after it goes down.^[2] If you used a weed-and-feed product, find the bag and read its seeding interval.

Prepare the soil

Seed needs to touch soil. For a full renovation, Virginia Tech suggests tilling to a 4- to 6-inch depth before seeding, which is also the moment to mix in the lime and starter fertilizer your soil test calls for.^[1] Where there is some decent grass worth saving, you can skip the tiller. A few passes with a core aerator or a vertical mower prepares the surface instead.^[1] Seed scattered over existing turf with no soil preparation usually does nothing more than feed birds and wildlife.^[1]

Before you till or aerate, contact Virginia 811. Its guidance for homeowners is that there is no allotted depth before you need to contact Virginia 811, because many utilities are buried just a few inches below the surface,^[9] and the request should go in at least 3 working days in advance.^[9] Mark sprinkler heads and shallow cable runs yourself while you wait.

After tilling, rake out dead clumps, roots and stones, fill low spots, and smooth the surface so the new lawn mows evenly.

Seed at the full rate

Virginia Tech's recommended seeding rates per 1,000 square feet are 6 to 8 pounds for tall fescue, 2 to 3 pounds for Kentucky bluegrass, 4 to 6 pounds for perennial ryegrass and 3 to 5 pounds for fine-leaf fescues.^[3] Seed at the full rate: a thick, fast stand is the main defense against the weeds that come up with a fall seeding.^[1]

A starter fertilizer is one of the few times extra phosphorus makes sense; up to 1 pound of phosphorus per 1,000 square feet can be justified at establishment even without a soil test calling for it.^[1] Fungicide-treated seed helps protect seedlings from damping-off.^[1] Spread half the seed walking one way and half walking across it, then rake lightly so most seed is just covered and press it in by walking or rolling.

Water and mow the new grass

After seeding, water lightly and frequently until the seed has germinated and started to establish, but not so heavily that it washes away or drowns the seed.^[1] Newly seeded lawns need more frequent watering for the first three to four weeks,^[5] then you cut back gradually to push roots deeper.^[1] Tall fescue seed usually germinates in 4 to 7 days; most Kentucky bluegrass needs 10 to 14.^[4]

Mow when the new grass needs it, with a sharp blade on firm soil, and never remove more than one-third of the leaf blade at a time.^[1] Hold off on weed killers: Virginia Tech says herbicides may typically be applied after the second mowing on new turfgrass, with some exceptions,^[2] and seedlings are much more sensitive to chemicals than mature grass.^[1] Read the label first. Our guide to keeping a renovated lawn thick covers the first year and after, and getting rid of weeds without killing grass covers the weeds that come back.

Stop and call a pro if

• The yard needs regrading, fill or drainage work, or water runs toward the house. Under Virginia's contractor regulations, grading is landscape service contracting,^[10] a trade regulated by DPOR, so check any contractor's licence.
• Bermudagrass or another perennial grass weed is still green after two rounds of spraying.
• The area is a steep bank or so large that tilling and seeding by hand would take more than a weekend or two.
• Large areas keep dying after you correct the soil, water and mowing; the cause may be disease or grubs that need identifying.

See all lawn and landscaping answers, browse lawn renovation services, or look up lawn and landscaping businesses around Blacksburg. If you would rather hand the job off, describe the renovation once and local businesses quote it.