Seasonal care for trees & shrubs: Mulching


Mulching with organic mulches (e.g. leaves, needles, hardwood and softwood bark and wood, grass, cocoa hulls, straw, etc.) helps to maintain tree health by aiding in water retention, inhibiting weed development, protecting from lawn mowing equipment, offering a layer of insulation during cold weather and adding organic matter into the soil (Carlson, 2003). At planting or transplanting time add a mulch layer 2-4″ deep around the tree as wide as you can tolerate but, to avoid stem damage, not against the trunk.  Mature trees can be mulched at any time.

Over time this mulch will break down and decompose; therefore it is important to make the necessary additions each year. Before making any additions, lightly and thoroughly rake existing mulch to break up compacted or crusted layers (Carlson, 2003b).  Mulching may act as an alternative to fertilization if coarse wood chips or leaves are used (Hagen, 2003).

For more information : Tree mulching booklet (.pdf) and Mulch in managed landscapes (.pdf)

More information on each step:

Authored by Rebecca Koetter, Gary R. Johnson, and Dave Hanson: University of Minnesota
Funded in part by USDA Forest Service: Northeastern Area
Chart designed by Andrew Rose:

Download & print your own poster or magnet copy of the “Seasonal Care for Trees and Shrubs in Northern U.S. Climates”

Rebecca works on urban forestry outreach education programs with the Department of Forest Resources in St. Paul.

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