Winter is coming: Time to put your garden to bed

It’s just about time to get your garden ready for winter. If you use terra cotta containers for your plants, store them inside or somewhere protected from rain and snow until spring.

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’re out of the rain. These containers absorb water, and the freeze-and-thaw cycles of winter can crack them if they’re left outside.

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

Options for leftover soil

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 you do use the growing medium for a second year, be sure to mix equal parts of the old mix with fresh soilless mix next year — and avoid reusing growing medium in containers that had any problems with disease. At home, we add old growing medium to our compost pile.

Forcing winter blooms

Certain bulbs like daffodils, hyacinths, tulips and crocuses are excellent for forcing in pots in the greenhouse or home. First, they need to be chilled for six to 10 weeks at 40 degrees Fahrenheit or below to make sure they get the dormant period they need.

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. Don’t let the pots dry out.

Protect bulbs from critters

When you bring them inside, acclimate them gradually if you can, keeping them at 50 to 60 degrees for a few days before exposing them to your regular indoor temperature.

Try pinning garden netting over freshly planted beds of bulbs to discourage chipmunks and squirrels from digging them up. This won’t work very well when drifting bulbs into shrub and perennial borders, though, since the bulbs will be spread out over a larger area and existing plants will get in the way of the netting.

Remove the netting in early winter when the ground is frozen, or in early spring. A light layer of mulch over the netting will help hide it. Spreading blood meal over the bed might also help repel the chipmunks and squirrels.

I’ve had success using a granular animal repellant sprinkled on top of the areas where the bulbs are planted. And, although it’s not feasible on a large scale, small pockets of bulbs can be protected by covering them with chicken wire or other mesh with about 1-inch openings underground; bulbs will grow through the chicken wire in spring.

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