Leave the leaves, please, for natural mulch
Shredded leaves make good mulch for your garden beds. Serious gardeners may consider renting a shredder, but be sure to use ear and eye protection when shredding leaves. Using a shredder is a time-consuming and noisy process, but it results in finer leaf mulch. For the average gardener, a lawn mower with a bag to catch the leaves is adequate for this job. The mower doesn’t cut the leaves up as finely as a shredder, but it works a lot faster. Ground-up leaves also decompose more quickly if you are using them in a compost pile. I do not shred leaves for my mixed borders at home. I simply let the leaves that fall into them remain as mulch. This saves a lot of time and has worked well in my garden.
For perfect perennials
In general, it is not necessary to mulch established perennial borders. Leave perennials up for winter interest and leave a light layer of leaves in the bed to provide some winter protection. Cut back perennials when they start looking bad. Any new perennials planted this year and especially those installed in late summer or fall should be mulched for the winter. The freeze-and-thaw cycles in spring can push newly planted perennials out of the ground.
Avoid drought stress
Pay attention to the unusually warm and dry weather in our area. If the dry weather continues, be sure to give supplemental water to plants installed over the last couple of years — especially evergreens. It is easy to forget about watering during November’s colder weather, but recently planted evergreens should not go into winter under drought stress. This stress increases the chance of winter burn. Evergreens can lose moisture from their leaves faster than the roots can replace it from frozen ground when there is low soil moisture, freezing temperatures and blowing wind. Make sure the root balls of evergreen trees are thoroughly moistened when watering by applying water to the base of the plant. Densely branched evergreen trees can shed water from rain or a sprinkler away from the root ball.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.