Chill bulbs for six weeks before bringing them inside

Certain bulbs, such as daffodils, hyacinths, tulips and crocuses, are excellent for forcing in pots in the greenhouse or home. They need to be chilled for six to 10 weeks at 40 degrees Fahrenheit or below to fulfill the requirements of a dormant period.

Plant them in pots in the fall and leave them in a cold place before bringing them inside for forcing. Place the pots in a cold frame outside, plunge the pots into the ground and mulch.

Do not allow the pots to dry out. When they are brought inside, gradually acclimate them to inside conditions, keeping them at 50 to 60 degrees for a few days.

• Terra cotta containers are best stored out of the elements for winter. When plants in these containers are finished for the year, dump out the growing medium and store the pots in a garage or shed so they are out of the rain. These containers absorb water and the freeze-and-thaw cycles of winter can crack them if they are left outside.

If you need to leave them outside over winter, then it is a good idea to elevate them above the ground, store them upside down, and cover them with a tarp to keep the pots as dry as possible.

• Any soilless mix from window boxes or containers can be discarded, mixed in a compost pile, blended into a garden bed or kept aside for one more year.

If the growing medium is used for a second year, mix equal parts of the old mix with fresh soilless mix next year. Avoid reusing medium in containers that had any problems with disease.

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