Lawn | Orange County Master Gardener Volunteers

4–5 minute read

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

Lawn calendar

Routine Care

Fertilize established lawns in mid-September according to soil test results. If you don’t test, apply 12-4-8 or 16-4-8 at a rate of 1 lb nitrogen per 1000 square feet. Fall is a good time to apply lime if your soil test indicates that it is needed.

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

This is the best time of the year to control white grubs.

Watch for winter annual weeds. You can hand-weed or try a preemergent.
Control winter annual broadleaf weeds
Earth-wise Guide to Weeds

Special Tasks

Aeration (coring) loosens the soil and improves water and air infiltration. September is the best time because turfgrass roots are actively growing, speeding recovery. Use a device that removes soil cores. Chop up the cores and, if possible, distribute them by dragging with a span of chain-link fence or a mat. Moistening the soil the day before makes the job easier and more effective.

Because fall is the true growing season for cool-season lawns, it is the best time to renovate and seed. Lawns seeded in the spring die in the summer because their roots don’t establish before hot weather arrives.
Learn about lawn renovation

Seed anytime from the beginning of September to mid-October. For best results, wait until nighttime temperatures are in the mid-60s but before leaves are covering the lawn. Use a blend of turf-type tall fescues at 6 lb per 1000 square feet. Apply a starter-type fertilizer and keep the seedbed moist with light watering several times per day. Germination normally occurs in 10–21 days. Do not let the seedlings dry out.
Before seeding, aerate (core) your lawn to reduce soil compaction and control heavy weed populations.

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soil test
aerate
topdress

fertilize
lime

seed
mow
water

annual weeds
perennial weeds
grubs
disease