Tips on composting to improve garden soil and starting seeds for annuals

We have two freestanding plastic composters in our home garden so we can do our small part in reducing waste going to a landfill. Continue putting organic material from the kitchen in the composter during the winter. Since it keeps the material secure, dogs and other animals cannot get into it. Our two dachshunds would have a heyday with kitchen waste if they could get to it.

Compost results from a process in which organic matter is collected, mixed and allowed to decompose. Compost can be used to amend soil, or as a mulch layer on garden beds and around trees.

In nature, deciduous leaves create a mulch layer that eventually decomposes. Like human-made compost, this natural recycling process returns nutrients to the soil and improves soil structure, and it is one reason why native plants growing in natural ecosystems usually do not need more fertilizer than nature provides. Composting reduces the amount of garden debris that ends up in landfills and improves your garden’s soil.

Now is the time to start annuals that get off to a slow start, such as pansies, violas, petunias, snapdragons, and lobelia. Read the seed packets to determine how much time the seed will take to germinate and develop to a stage appropriate for planting outside.

While garden centers offer many favorites, you will have many more choices if you make the effort to grow your own. Use grow lights to ensure success. A fluorescent type hung on a chain works best, as you can adjust the level to keep the light at an optimum 8 to 12 inches above the seedlings. Providing bottom heat for the seedlings will also improve results. Heat mats or cables can be purchased at your local garden center.

Thin seedlings as needed, especially after the first set of leaves forms to prevent overcrowding and keep the best plants. Remember to include a few extras when you are sowing, but not too many.

Don’t forget to water any evergreens planted in outdoor containers during warm spells this winter. The weather has been below freezing for several weeks in the Chicago area, so there has not been a need to water them yet. Evergreens continue to lose water through their leaves and will be more likely to suffer winter burn if they dry out in the containers.

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