Lawn | Orange County Master Gardener Volunteers

3–4 minute read

Our tips are for cool-season lawns like bluegrass and fescues.

Routine Care

Do not fertilize. Roots decline with the arrival of hot weather and cannot support the added top growth.

Mow to 3–3½ inches.

tips

Mowing shorter than 3inches causes multiple problems:

Close mowing can injure or kill the turfgrass clump growing point.
Because short blades cannot photosynthesize effectively, vigor is reduced, increasing susceptibility to pests and disease.
Weed seeds germinate more easily because more sun reaches the soil.
Rain hits and compacts the soil.

Don’t remove more than ⅓ of the grass height. Mowing is pruning and grasses respond by redirecting energy and nutrients away from roots in order to produce new leaves, resulting in a weaker root system. Drastic cuts also increase water loss to stressful levels.

Travel north–south on one mowing and east–west on the next. This keeps growth upright and reduces lawnmower ruts.

Leave grass clippings on the lawn. They decompose quickly and can return up to 25% of the lawn’s fertilizer. If clippings are too plentiful, use them as mulch or, if they do not contain herbicide, let them dry a bit and then add to your compost.

Supplement rainfall as needed to provide 1 inch of water weekly. This should wet the soil to a depth of 4–6 inches. You can check by probing the soil with a screwdriver.

problems

Check for white grubs.

Consider a pre-emergent.

tips

Cool-season lawns need to rest for the summer, so use a pre-emergent that does not contain fertilizers. Products containing dithiopyr also provide post-emergent control for young crabgrass.
Japanese stiltgrass (Microstegium) germinates before most other weeds. Application timing is challenging because germination is based on soil temperature, which varies from year to year. Normally, apply pre-emergent in early March. If spring is early, do so in late February.
Apply the first round of crabgrass prevention in late March–early April. Because spring weather varies, use flowering as your cue. The most effective period begins when forsythia is blooming and ends when dogwoods are blooming. Apply a second round about 6 weeks later.

Preemergent control
NCSU recommendations for stiltgrass control
Crabgrass prevention

Special Tasks

Wait until September to aerate. Aeration should happen when turfgrass roots are actively growing to speed recovery.

Wait until fall to seed or renovate your lawn. Lawns seeded in the spring don’t last through the summer because their roots don’t establish before hot weather arrives.

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soil test
aerate
topdress

fertilize
lime

seed
mow
water

annual weeds
perennial weeds
grubs
disease