Tips for growing gladioli and lawn seeding in late summer

I have fond memories of growing gladioli as a kid growing up in Nebraska — and at this point in summer I’m seeing them in bloom around the Chicago area.

The gladiolus produces a large, showy flower spike that lasts for several days whether in the garden or in a vase. To get the most out of this bloom for decoration inside, cut when the lowest blossoms have started to show color, and place the cut stem in water as quickly as you can. In the garden, if you stagger planting gladioli every couple of weeks, you’ll have flowers over a longer period of time. This plant likes full sun and well-drained soil.

Lawn seeding

Mid-August to mid-September is a good time to seed bare spots in your lawn; just choose a seed mix that’s 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 uniform look.

First, prepare the site for seeding by removing weeds and loosening the soil — loosening soil before seeding is an important step. Low areas will need additional topsoil, and you should rake out large clods, stones, and debris to create a smooth seedbed. Then gently rake in the seed. Keep the soil moist! On warm days this might require watering two or three times a day; a light layer of compost spread over the soil can help maintain moisture. Bluegrass takes about two weeks to germinate, and keeping the grass seed moist helps successful germination. As the new grass fills in, you can scale back watering to less frequent but deeper soakings.

When you’re establishing a lawn by seed, you can expect weeds to make their way in before the grass can get fully established. You should mow a newly seeded lawn four times before treating it with herbicide for weeds. Pulling the weeds is also an option, and you can do this before mowing is necessary.

Don’t forget to check the oil and clean out your lawn mower’s air filter on a regular basis. Mowers at homes with large lawns have built up a good amount of operating time at this point in the year, and letting a mower run out of oil could ruin its engine. It’s also a good idea to sharpen the mower blades about every eight hours of use.

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