Mulch has many benefits--if the material is organic, such as leaves or shredded bark.
It will break down and feed the valuable organisms in the soil. It will insulate the soil around the roots of plants to protect them from sprouting prematurely in late winter. A ring of mulch around trees protects their bark from damage by lawn mowers and stringer trimmers.
Here are some tips for winter mulching.
Don't mulch too soon. Wait until the ground is good and cold; the goal is not to keep the soil from freezing but to keep it frozen during brief late-winter warm spells. Cold soil keeps plants dormant so they do not sprout when there still is danger of freezing.
Mulch for free. Fallen leaves are an excellent mulch material, especially for perennial beds. Shred them so they don't blow around by spreading them on the lawn and running over them with the lawn mower. Composting them first will reduce weed seeds. You also can purchase mulch, such as shredded bark. Medium-textured mulch is best.
Don't mulch too deep. Make an even layer 1 to 2 inches deep in perennial beds and 3 to 4 inches deep in a wide circle around trees and shrubs. Pull the mulch a couple of inches away from the crown of each perennial or the trunk of a tree so it does not invite rot or shelter gnawing rodents.
For answers to your mulching questions, call The Morton Arboretum Plant Clinic at 630-719-2424 or visit us online.