Winter interest is one thing, vole damage is another
I prefer to wait to cut back perennials until early spring so that there will be some winter interest in the garden. Some perennials such as hosta do not look good after being frozen, so it is best to cut them back in fall as they flatten to the ground.
Use a general rule of cutting back the plants that do not look good late in the fall and leaving the remaining plants to cut back in early spring.
You may want to consider cutting more perennials back in the fall if you have had problems with voles eating your plants over winter. Voles are compact rodents with stocky bodies, short legs and short tails and can be mistaken for mice.
Voles 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 eat the bark of trees and shrubs during the winter, which causes the most serious damage and can kill the trees.
Gardens planted 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 cleared away 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 works best so that the containers with bulbs do not freeze solid.
Water the bulbs in well at planting and provide some supplemental water as needed during remainder of fall. The bulbs form 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, net the bulbs when you have them outside for protection.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.