When to apply crabgrass preventer in Greene County, Ohio

Do this in April

• Mowing

  Mow at 3 to 4 inches, once or twice a week.

  Buckeye Turf recommends mowing at least once a week, twice in spring and fall when growth is fast. Keep to the one-third rule and keep the blade sharp. [1][2]

• Seeding

  Seed or prevent crabgrass. Usually not both.

  Most crabgrass preventers also stop grass seed from germinating, for up to four months. If you need to seed this spring, OSU says mesotrione at seeding is the best option. [3][4]

• Fertilizer

  A light, slow-release feeding is fine.

  OSU suggests 0.5 to 1.0 pound of nitrogen per 1,000 square feet in spring, mainly slow release. Choose a fertilizer with little or no phosphorus (the middle number) unless a soil test says you need it, and sweep granules off driveways and walks. [3][4]

• Crabgrass and pre-emergents

  Apply preventer when 2-inch soil reaches about 50°F.

  OSU names pendimethalin, prodiamine and dithiopyr as common preventers. Their trials found early-April applications (before germination) work better than March ones. For heavy crabgrass, apply as late as you safely can before it germinates. [5][6]

  This depends on soil temperature, not the date.

  This is the nearest Ohio State weather station with live soil temperatures, just north of Greene County. It reports soil temperature at 5 cm (about 2 inches), the depth OSU uses for crabgrass timing.

  Check today's reading at the OSU CFAES Weather System, Western Agricultural Research Station (South Charleston, Clark County)

• Grubs and weeds

  Treat wild onion and wild garlic; preventive grub season opens.

  OSU says April to early May is the time for wild onion and wild garlic. If grubs have damaged your lawn before, chlorantraniliprole can be applied as a preventive from early April through July. [7][8]

• Aeration

  Core aerate if the soil is compacted or thatch is over ½ inch.

  OSU says spring and fall are typical times to aerate in Ohio, any time the soil is moist enough to pull cores. Pull about nine cores per square foot; spike tines don't work. [3][10]