Your turf lawn may need some summer help

From mid-August through mid-September, add seed to bare spots in your lawn. Choose a seed mix that is appropriate for the amount of sun at your site.

Grass grown from a mix blended for shade can look different from grass from a mix blended for sun. If your yard has adjoining areas of full sun, shade and partial shade, use a single mix of grass varieties for both sun and shade to give the lawn a more uniform appearance.

Prepare the site for seeding by removing weeds and loosening the soil. Low areas will need additional topsoil. Rake out large clods, stones or debris to create a smooth seedbed. Then gently rake in the seed.

Keep the soil moist. On warm days, this may require watering two or three times a day. A light layer of compost spread over the soil helps keep seeds moist.

It is important to keep the grass seed moist for successful germination. Watering can be scaled back as the new grass fills, but make sure that less frequent soakings penetrate more deeply.

Bluegrass takes about two weeks to germinate.

When establishing a lawn by seed, you can expect weeds to come in before the grass can get fully established. You should mow a newly seeded lawn four times before treating with an herbicide for weeds. Pulling the weeds is also an option and can be done before mowing is necessary.

• It is important to identify the insects on your plants before treating with an insecticide to determine whether or not the insect really is a problem. If it is, try to assess whether the damage being done warrants control.

The presence of insects feeding on the plants should not warrant automatic treatment. Some insects are beneficial and help control other insects naturally. If an identified pest is causing significant damage, it is important to use a correct control with proper timing. If a variety of treatments are available, use the least toxic control possible.

• The weather has turned warmer and drier recently, so any plants you have installed over the last couple of years may benefit from some supplemental watering until there is a substantial rain. Any plants installed this year will need close attention to watering during these hot and dry periods.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.