Should a Minneapolis suburban HOA mulch evergreen trees? Are there benefits...
Absolutely. Mulching trees provides a number of benefits in addition to improving the look of the landscape. Two b=good options for large landscapes are shredded wood 3-4" thick, or a combination of rock mulch with landscape fabric underlayment to prevent rock from working into the soil. Fabric is not recommended for wood mulch due to the fact wood mulch will decompose on top of the fabric and weed seeds will germinate there. Black plastic is never recommended as it blocks all water from reaching important plant root zones.
Some benefits of mulch:
- Mulch reduces weed seed germination by blocking light. This can reduce maintenance time.
- Mulch will help conserve soil moisture reducing irrigation needs and reducing erosion.
- A mulch ring of a minimum of 6-ft in diameter (larger for evergreens) will protect plant roots and trunks / stems from mechanical damage from mowers, foot traffic, and weed whips. This will improve plant health and reduce maintenance time.
Note that for dense evergreens such as spruce, the mulch ring should expand a minimum of 1-2 ft from the edge of the branches to provide space for mowing around the mulch edge. Note too that edging is not recommended for mulch diameters that are too tight as the edging can heave: http://www.extension.umn.edu/garden/landscaping/implement/poly.html
- Mulch will prevent soil from splashing onto lower leaves / branches potentially reducing soil-borne diseases.
- Mulch should be pulled away from tree trunks and stems to prevent moisture build up. See Diagram 1 here: http://www.extension.umn.edu/garden/landscaping/implement/planting_trees.html
Feel free to reply with additional questions.