Green Garden: Laying the Groundwork

Seattle Magazine, March 2007
By Roddy Scheer

If you’ve sworn off pesticides, you’ve taken an important step towards environmentally-friendly gardening. But there’s much more work to do, starting from the ground up...

Soil Matters

Building healthy soil is the key to creating a successful garden, says Amy Ockerlander of Seattle Tilth, a pioneering non-profit focusing on green gardening and urban ecology. “Adding compost or incorporating organic matter into your soil is going to help your plants out from the very beginning because that’s what is supporting your plant life, ” says Ockerlander, one of four gardening gurus staffing the organization’s phone- and e-mail-based Natural Lawn and Garden Hotline. Compost helps soil retain moisture in the summer, and yields dividends year-round by harboring micro-organisms and fungi that improve and maintain soil health and help plants thrive.

Organic waste from your garden, including leaves and grass clippings, can build a compost pile or fill a compost bin. A good mix of greens and browns turned on a weekly basis should create usable compost within six months.

The Seattle Conservation Corps, a project of the city’s parks department, sells excellent compost bins for yard waste for $25 at its Sand Point Magnuson Park headquarters (7727 63rd Ave. NE, Suite 201, http://www.seattle.gov/parks/scc/, call for directions, 206.684.0190). While there, pick up a rodent-proof “green cone” ($25) to compost your kitchen food waste.

Pesky Pests

One of the hallmarks of so-called natural gardening is the rejection of the synthetic pesticides so common these days. But then what do we do about those pesky pests? Seattle Tilth recommends constructing barriers for specific types of problem insects and choosing specific native plants that are naturally resistant to common pests.

If such techniques don’t prevail, some green gardeners are turning to BT, a living, organic bacteria-based insecticide that kills many of our region’s common garden pests (cabbage loopers, gypsy moths, spruce budworms, tent caterpillars, tomato hornworms, and fall webworms) but doesn’t harm plants, people or other wildlife. And since BT is a living organism, it doesn’t pose any chemical pollution problem. Another environmentally alternative is insecticidal soap, which essentially scrubs vital oils from insects’ bodies, rendering them unable to survive. Such treatments are available at big local nurseries such as Sky (18528 Aurora Ave. N, Shoreline; 206.546.4851), Swanson’s (9701 15th Ave NW; 206.782.2543) and City People (2939 E. Madison St.; 206.324.0737).

Fertilizing

Besides being greener, organic plant fertilizer just plain works better than its traditional chemical counterparts, mostly because it attracts beneficial micro-organisms to the soil which invigorates your garden’s base layer naturally. And while residue from chemical fertilizers (i.e. the chemicals not taken up by the plants) ends up in our streams and groundwater supply, there’s no such problem with organic fertilizer. Varieties recommended by Ockerlander include Down to Earth, Dr. Earth, Whitney Farms and Ballard-based Walt’s, all of which are also widely available at local nurseries.

Native Plants

Once a specialized approach to gardening in the Pacific Northwest, today “going native” is de rigueur. “Native plants are accustomed to our environment, including our droughty summers and wet winters,” says Ockerlander. They also provide habitat and food sources for beneficial critters (like worms that help aerate the soil naturally) and birds that look for such items in your backyard.

Some of her favorite native plants are the Evergreen Huckleberry and Service Berry, both shrubs with edible berries; Sword Fern, a year-round green plant that thrives in dry shade or sun; Salal, a groundcover; and Red Twig Dogwood, a tree that’s showy in the fall and reveals fire engine red twiggy branches as it waits out the winter.

Native plants are regularly stocked by big local nurseries (ask their staff gardeners to direct you to some of their favorites) and several smaller local nurseries specialize in Pacific Northwest natives. For a list, go to the Water and Land Resources Division of King County Natural Resources and Parks Web Site at http://dnr.metrokc.gov/wlr/pi/npnursry.htm.

Invasive Species

Invasive plants species are proliferating thoughout the Seattle area, in some cases taking over our backyards, greenbelts and city parks. English Ivy, for one, has been known to choke the life out of neighboring trees, sometimes causing property damage due to falling limbs, while another well-known invasive bad guy, the Himalayan Blackberry, crowds out healthier native species in order to spread its sweet fruit. Rats love both plants, sometimes taking up residence in particularly abundant stretches. Remove these plants—if that’s not an option, mowing either down every spring will help prevent them from generating seeds and spreading later in the year.

According to the Washington State Noxious Weed Board, some up-and-coming invasives that are starting to cause problems as they escape from residential gardens around Seattle include Common Fennel, Purple Loosestrife, Scot’s Broom, Spurge Laurel, and Yellow Archangel. Gardeners are advised to steer clear of these plants if they see them at a nursery, and to pull them out if they pop up in the backyard. King County lists other invasive garden ornamentals to stay away from on its online Noxious Weed List (http://dnr.metrokc.gov/wlr/lands/weeds/weedid.htm), which features color photos to help novices identify the usual suspects.

Ditch the Lawn?

According to Seattle Audubon, the typical lawn produces little habitat for wildlife, hogs municipal water supplies and generates significant amounts of pollution from the use of gas-leaking lawnmowers, synthetic fertilizers and pesticides. Seattle Audubon recommends reducing or replacing your lawn with more planting areas featuring native species. If you can’t bear life without a lawn, mow it high and often, and leave the clippings where they land to serve as natural in situ mulch and compost. For a virtual toolkit of lawn care and replacement tips, go to Audubon’s Gardening for Life Web Site, http://www.seattleaudubon.org/conservation.cfm?id=287.

Reduce Water Waste

Seattleites waste a lot of water trying to keep their grass green all summer long. Seattle Tilth recommends letting your lawn go dormant during our hot dry summers, and keeping an eye on any opportunistic weeds looking for an ‘in’ while the grass takes the season off. Plants, on the other hand, may need a little coddling to make it through the summer, so urban gardeners should employ a water-saving soaker hose which essentially trickles out the H20 right to plants’ roots where its needed most. Even better, waterwise gardeners can plot out, put together and install a drip irrigation system out of hose bibs and emitters available at any big nursery or home improvement store. The Saving Water Partnership, a coalition of local utilities bent on water  conservation, offers a free step-by-step guide on how to create a drip irrigation system free on its website (http://www.savingwater.org/docs/Dripfactsheet.pdf). Those with automatic sprinkler systems might consider dialing back the flow and reducing frequency of watering if possible, and may be eligible for a rebate on a tune-up or upgrade from the Saving Water Partnership (http://www.savingwater.org/outside_sprinklers.htm). And don’t forget that you can save water -- and money on your utilities bill -- by using a rain barrel to collect some of that precipitation you’ve been complaining about for re-use in the garden. Seattle Conservation Corps (contact listed above) sells them for $65.

Where the Wild Things Are

You can help offset the annual loss in Washington state of 35,000 acres of wildlife habitat to housing and development, by creating a wildlife-friendly garden with the help of the Backyard Wildlife Sanctuary program (425.775.1311; http://wdfw.wa.gov/wlm/backyard/). The program, created by the Washington Department of Fish and Wildlife (WDFW) in partnership with National Wildlife Federation, encourages private homeowners to green up their backyards by providing natural food and shelter for local free-ranging wildlife species, from spiders to raccoons to hummingbirds. WDFW’s Backyard Wildlife Sanctuary packets (available for $5 from the agency) are chock full of region-specific information on how to best arrange specific types of native plants to provide habitat for wildlife. The packets also include an application form to enroll your yard as an official backyard sanctuary for an additional $5. Enrolling in the program entitles you to a waterproof sign so your neighbors will know just how eco-chic you are.

Seattle Audubon also produces its own much-lauded “Introduction to Naturescaping” packet, with information on community resources for creating and maintaining a backyard friendly to resident and migratory birds. The organization also sells Stephen Kress’ bible of gardening for wildlife, The Bird Garden, as well as a wide range of other tools and resources, at its retail store in Seattle’s Wedgewood neighborhood (8050 35th Ave. NE; 206.296.7266, http://www.seattleaudubon.org).