Mulch that Garden!



 Every spring and every fall I ponder purchasing a huge mound of garden compost (I need more than a unit—7 yards—to cover my garden). From a practical standpoint, spring seems a good time because it’s easier to work around perennials, which either haven’t emerged or they are relatively small and haven’t spread their “wings,” so to speak. But it often is wet and there’s not much heavier than rain drenched mulch (unless its gravel or rock). Mulching in the fall typically offers better weather making it a more enjoyable (ha!) experience. I have to confess: I haven’t mulched in years. I haven’t been able to talk myself into lugging dozens of wheelbarrow loads from the driveway in front to the garden in back (and down the hill and over the stairs). I get tired just thinking about it.

My soil and plants are telling me it’s time to take the plunge. In the maritime Northwest, it really doesn’t matter when we mulch. A 2009 Quick Poll says Random Acts of Gardening readers are most likely to mulch in both the spring and fall (55%). There isn’t a dramatic difference between mulching just in autumn (22%) or just in the spring (16%). Nine percent fall into my camp and don’t mulch at all. According to a 2010 Quick Poll, when readers do mulch, they most often use a combination of compost and bark dust (41%). Thirty-three percent use compost (12% use their own compost) and 17% use bark dust.

There are many “pros” to mulching and not many “cons.” On the con side, it is hard work (though mulch can be blown in making it a lot easier, albeit more expensive) and weed seeds are likely to come along as part of the package. However, the benefits far outweigh the drawbacks (I’m definitely talking myself into another unit of garden compost).

Benefits of mulching:

  1. Keeps weeds down (bare soil tends to attract unwanted vegetation) and makes it easier to weed when they do appear (it’s easier to pull roots out of mulch than soil).
  2. Conserves soil moisture by reducing evaporation and makes it easier for water to penetrate the soil.
  3. Helps prevent soil compaction and erosion caused by rain and wind.
  4. Keeps soil from splashing onto leaves (plants look better and it helps to prevent soil-borne fungal diseases).
  5. Decomposing organic matter adds humus to the soil, encourages the growth of microorganisms and keeps the soil loose and airy, which is good for root growth.

Fall mulching helps soil retain heat, especially helpful in areas prone to cycles of freezing and thawing. Woody plants continue absorbing water, allowing plants to go into winter with more moisture, which in turn minimizes foliage desiccation. If you mulch in spring, do it after the soils warm up, otherwise plant growth may be delayed. Also, stepping on wet soils in early spring to spread the mulch likely will cause soil compaction.



Courtesy of Madison Tree Care & Landscaping

 Layer the mulch two to three inches over the soil—slightly deeper if you have sandy soils—but keep it from having direct contact with tree and shrub bark because excess moisture can cause rot and make the plant more susceptible to disease. Warning! Mulch volcanoes (aka mulch mounds) are a “no-no!”

Here’s a mulch spreading tip to help with your perennials and smaller plants: If you happen to have a few spare one- or two-gallon nursery containers, put them over top of your plants and then shovel the material right onto your bed.

A few sources for bulk garden mulch and gravel: Boring Bark & Landscape Materials (Boring), Farmington Gardens (Beaverton), Grimm’s Fuel Company (Tualatin), Lane Forest Products (Eugene and Springfield), Marr Bros. Bark (Monmouth, 503.838.11830), McFarlane’s Bark Inc. (Milwaukie), Mt. Scott Fuel Co. (Portland), Phillips Soil Products Inc. (Canby), Prineville Landscaping Materials & Nursery (Prineville), and Rexius (multiple locations). Be sure to ask about the source of the material for the compost; you don’t want Verticillium to be invited into your garden.

Ibuprofen here I come!