Most perennials and grass foliage need not be cut back in fall

Perennial and grass foliage can add a lot of appeal to the winter landscape while being beneficial for overwintering pollinators and wildlife. That’s why I prefer waiting until early spring to cut back perennials.

Some perennials, such as hostas, do not look good after being frozen so you can cut them back in fall as they flatten to the ground. I also wait until spring to cut hostas back, though and in one mass planting beneath an oak tree, I do not remove the foliage at all, as the new hosta growth pushes up through the old foliage.

One option is to follow a general rule: cut back plants that look unsightly in late fall and leave the remaining plants until early spring.

You may want to consider cutting more perennials back in the fall if you have had problems with voles. Voles are compact rodents with stocky bodies, short legs, and short tails and can be mistaken for mice. They do not hibernate and are active throughout the year, mostly at dawn and dusk.

Voles primarily eat the stems and leaves of various grasses, but they also consume other vegetation. They will eat the bark of trees and shrubs during the winter, which is typically the most serious damage to be concerned about. Gardens with low-lying landscaping, such as arborvitae, spreading yews, junipers, and cranberry cotoneaster have higher potential for vole activity.

Voles are the most prolific when they have abundant amounts of vegetation and cover. The damage is likely to be more severe during extended cold spells with deep snow cover. Eliminate weeds and dense ground cover around lawns to make these areas less able to support voles. Mow lawns and other turf regularly and cut back vegetation from the bases of trees and shrubs as winter approaches in areas where there is vole activity. Also, it is a good idea to pull mulch back away from the base of trees and shrubs and keep the snow clear from the base of young trees. Reducing cover makes voles more vulnerable to predators such as hawks and owls. In general, removal of cover is very effective in preventing damage done by voles.

For a unique bulb display in spring, plant bulbs in containers. It is possible to layer bulbs in the container to create a dramatic display of bulbs. Keep the containers in an unheated garage over winter. An attached garage will work best so that the containers with bulbs do not freeze solid on a consistent basis. Water the bulbs well at planting and provide some supplemental water as needed during the remainder of fall. The bulbs will be forming roots during this time. You may need to water the containers in late winter as temperatures begin to warm up.

Move the pots outside as the weather warms in spring and the bulbs will grow and flower. Move the bulbs back in the garage if a hard freeze is predicted.

If you have planted tulips that deer prefer, it will be a good idea to net the bulbs when you have them outside.

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