Mulch Matters
Kim Halberg, Anoka Country Extension Master Gardener
“What’s the difference between using mulch and rocks?” a neighbor recently asked. The simple answer is that they are both mulch and both have their merits.
They both add protection and esthetic cover, while keeping soil temperatures balanced. Mulch is like pulling down a shade in a room; it cuts off light to those pesky weed seeds so they don’t germinate and compete with the needs of the plantings.
Mulch falls into two basic categories of organic and inorganic. Some people prefer the later, such as rock around their home because of the stability of the product when it rains. However, there is the challenge of proper water, oxygen and nutrients in the soil, thus affecting the plantings. Remember when plastic was king in landscaping? Plantings were suffocating and dying of thirst. Landscape fabric has been introduced as an alternative. Many home and commercial landscapers are moving toward no fabric under organic mulches that break down into soil. The only caveat to this is that slower decomposing mulches may utilize the nitrogen in the soil, so a fertilizer is recommended if signs of this deficiency is noticed. Although organic mulches do require regular application, weeds are easily plucked out. There are no heavy shovels of rocks to remove after wind and time has deposited a layer of soil, creating a perfect storm of weeds.
Besides the classic two mulches of rock and wood chips, there are choices limited only by one’s imagination: carpet, geo plastic textiles, cocoa shells, bark, pine needles, chopped leaves, straw, hay, newspaper without ink, corn cobs, wine corks (have a BYOB party) and snow. Known as the poor man’s mulch, snow is a beautiful thing until it melts and temperatures drop. Leaving old vegetation to overwinter on plantings can be a cozy blanket of protection and a winter chalet for beneficial creatures. Even discarded wool fiber leftover from production is being turned into “woolch” to form a soft layer of garden fleece. Not ba-a-a d, eh?
How much and what type for what plantings? Some products work best around fruits and vegetables that do not have dyes in them. In the case of trees and shrubs, keep mulch to one inch or less around the base of the trunk/stem using a doughnut hole method, instead of the volcano pile up around the base of the planting, which can cause distress to the plant. This also applies to flowering annuals and perennials. When first applying the mulch, lightly ring each planting with a circle of mulch, then fill in the open areas with 2-3 inches of mulch. If heavy cover is wanted for a pathway or demarcation line between turf and a wooded area, 4-5 inches would suffice.
For ornamental areas, spreading mulch can be like frosting a cake; the color sets the tone for the elements added on top. It’s a personal preference of monochromatic or a dramatic contrast. Over the years, designers have been leaning toward tones that let the plantings shine rather than competing for attention. Visit our website: http://anokamastergardeners.org for more information on events, activities and how to Ask a Master Gardener questions.