Cover Story Plant Life On Fitness Northwest Living Taste Arts special Now & Then


Getting Covered
Bed down for fall with a nourishing blanket of mulch

Everything You Ever Wanted To Know About Mulching: Well, maybe you weren't afraid to ask, but who wants to admit that the specifics of mulching can be confusing? Is there another current gardening topic more politically correct? Gardeners are urged to just do it, but exactly how is the question.

I grew up in a garden grown huge from the benefits of feeding mulch, with hydrangea blossoms the size of bowling balls. My Dad raised racing pigeons, and the loft behind our house generated a seemingly endless supply of manure. Pigeon droppings are too "hot" to apply directly, so huge compost piles in the corner of the garden "cooked" the stuff until it cooled down. We kids dreaded the chore of having to dig into these disgusting piles and wheelbarrow the rich, black gold around the garden. Little did I guess that years later my favorite twice-a-year gardening task would be spreading a nicely rotted-down feeding mulch of chicken manure and bark. Along with its other benefits, mulching is a way to nourish the plants and soil, so I'm a little perplexed when I hear materials like straw or nutshells touted as garden mulch.

In a search for clarity, I turned to "the bible," Rodale's "Encyclopedia of Organic Gardening" (Rodale Press, 1959, updated 1999), which defines mulch as "a layer of material, preferably organic material, that is placed on the soil surface to conserve moisture, hold down weeds and ultimately improve soil structure and fertility." That seems straightforward, but the following pages list things like pine needles, corncobs and grass clippings as appropriate materials. Maybe for the vegetable patch, but I don't think these materials are what we want to look at garnishing our front flower beds.

Now In Bloom
Miscanthus sinensis 'Zebrinus' (grows to 6 feet, or a dwarf form to 3 feet), has green blades banded in irregular stripes of creamy gold. In autumn, tall spikes open to silky buff-colored flowers that catch the sunlight and are beautiful when cut and arranged with asters or chrysanthemums.
Most of us, after all, have experience only in our own gardens, so I decided to talk with a couple of landscape professionals who are out there most days of the year working in a variety of gardens. Diana McLeod of Northwest Botanicals does it all — design, installation and maintenance. She recommends mulching at least once and preferably twice a year. The ideal times are after the perennials have been cut down in the autumn, or in early spring just as new growth starts. Because of this year's drought concerns, she mulched most of her clients' gardens in March to conserve water through the drier months.

McLeod is a fan of Cedar Grove compost, made from Seattle's clean, green recycling. "As a top mulch, Cedar Grove accents the garden — its deep, black richness makes the plants 'jump' and adds the aesthetic punch our clients like," says McLeod. She appreciates that everything disposed of at the transfer station will be reused and make its way back into the garden. Depending on the condition of the soil, she applies Cedar Grove compost between 2 and 6 inches deep, and suggests spreading it on a dry day, because in the rain the compost tends to form clumps and harden. Over the months, the compost works its way into the soil, adding nutrients and water-retention capacity.

Robyn Atkinson, of Robynswood Landscaping, uses a well-composted, rotted-down feeding mulch one year, cow manure purchased from local dairies the next. During the rainy season (between November and March, when the garden is barest and wettest) she spreads one or the other about 6 inches deep. She warns that mulches tend to disappear quickly if not applied thickly. The biggest mistake is to use too little, Atkinson says, estimating that mulches have about a 50 percent shrink rate. Atkinson has a kind of Northwest-cottage planting style, with a great many different plants, including vegetables and fruit, squeezed into a fairly small area. By enriching and improving the soil she feeds the plants, maintaining the health and vigor of the garden.

Another thing I learned from Atkinson is a mulching technique that saves steps when tidying the garden. Simply let the dried leaves or spent blossoms fall to the ground among the plants as you clip, thus returning organic matter to the soil even more directly. This is easy, quick and saves time that can later be spent spreading on that mulch.

Valerie Easton is a horticultural librarian and writes about plants and gardens for Pacific Northwest magazine. She is the co-author of "Artists in Their Gardens" from Sasquatch Books. Her e-mail address is

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