It is time to plan for and order spring-flowering bulbs for your garden. These plants need well-drained soil, so any area that remains wet for long periods of time or has standing water is unsuitable for bulbs.
Most spring-flowering bulbs need a full-sun site. They require sunlight to store energy in order to bloom the following year. Bulbs prefer to have moist soil in spring and fall and to bake in the summer.
However, some more shade-tolerant bulbs will flower when planted beneath a high-branching tree, because they get some sun in early spring before the tree's leaves emerge.
If deer and rabbits are a problem in your yard, choose bulbs that are less attractive to them. Daffodils, ornamental onions (Allium), Siberian squill, snowdrops and winter aconite are recommended for areas where these animals are present.
Mid-August to mid-September is a good time to seed bare spots in your lawn. It is best to plant a seed mix rather than a single variety. Choose a mix that is appropriate for the amount of sun at your site. Though all grass species prefer full sun, some can get by with less sun than others.
Grass grown from a mix blended for shadier areas 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 blended for both sun and shade. Such a mix will give the lawn a more uniform appearance overall.
Prepare the site for seeding by removing weeds and loosening the soil. Level low areas with additional topsoil. Rake out large clods, stones or debris to create a smooth bed for the seed. Then scatter the seed and gently rake it in.
Keep the soil moist until the seeds germinate, or sprout, which will take anywhere from several days to two weeks. In warm weather, you may need to water the reseeded areas two or three times a day. A light layer of compost spread over the soil will help keep the seeds moist.
After the seeds sprout, water less often but more deeply as the new grass fills in. A good soaking followed by a few days when the water seeps down into the soil will encourage the grass to grow long, deep roots.
You can expect weeds to sprout in the reseeded areas before the grass can get fully established. Do not treat these areas with an herbicide until the grass has grown in enough that you have mowed it four times. In the meantime, hand-pulling the weeds is an option.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.