Thursday, April 5, 2018

Gardens… to mulch, or not to mulch?

March and April are ideal months to tweak your garden plans for the upcoming growing season.  Visit your favorite local garden center to gather ideas and ask questions, even if it is too early to place plants in the soil in your region.

Whether you’re planting natives, perennials, evergreens, edibles or ornamental annuals, each will benefit from selecting an appropriate mulch.  I recently checked various online sources and was quite surprised to find how much BAD ADVICE is being perpetuated regarding MULCH!  Think about the specific type of plant you intend to mulch; then let that plant’s needs guide your selection.

Evergreen trees and shrubs NEED and WANT acidic mulch over the entire root zone, if feasible.  Those sparkly white landscape stones are not acidic and create reflective heat; heat rises.  You will likely “toast” the bottom branches of your evergreens! 

 Instead, utilize shredded hardwood mulch, which eventually decays and provides nutrients.  If you wish to top-dress the root zone with organic matter/compost prior to covering root zone with 2-3 inches of shredded hardwood, your evergreens will thrive. The same top dressing and shredded wood mulch is great for perennials and shrubs.

Rubber mulch?  Fine for playgrounds to prevent injuries, but NOT fine for placement around herbs and veggies.   Rubber tires are repurposed into rubber mulch; aren’t rubber tires a petroleum-based product?  Keep this away from edibles, please!  (If you must use rubber mulch somewhere on your property, be certain your edibles are planted uphill from the rubber mulched area to prevent runoff during storms.)

Grass clippings?  Best to keep them out of your gardens entirely; either mulch them into your lawn to provide extra nitrogen for the grass, or place in compost bin with veggie kitchen scraps, straw, and used coffee grounds to create rich organic matter.

Landscape fabric?  Use ONLY under landscape stone or river rock.  Placing it beneath shredded hardwood (or softwood) mulch is a poor choice; shredded wood eventually will decompose ON TOP of the fabric, creating a comfortable nesting place for weed seeds.  This creates a larger task for a gardener to remove both weeds AND fabric!

Herbs and veggies? Mulching might be unnecessary, but if a plant has a large footprint in your garden--like zucchini or tomatoes—then I like to use a light covering of straw (NOT HAY—too many undesirable seeds in hay will cause weeds!)   

The bottom line:  MULCH WISELY!  Your plants will be happier and healthier.

M. Lynn Schmid,  Certified Master Gardener
 A.A.S. Landscape/Horticulture/Arboriculture