Non-Pests of the NW Garden: Lawns

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Oh, my aching muscles...

Turf War Truce

By Wendy Tweten

Slugs and snails, insects, moss and lichen, moles and mountain beavers: our gardens are filled with flora and fauna that we did not invite. The tricky part is to know when to act and when to sit back and simply enjoy the suburban-scale wild kingdoms that are our backyards. Welcome to a new feature that will explore the common yet curious creatures that share our outdoor spaces.


Sharing the Lawn With the Creatures at Our Feet

Before we begin I should admit that my lawn would bring the average suburban home-owners’ association roaring up the drive with torches and pitchforks. Years ago we tilled up the grass under the fruit trees and planted Eco-turf, a blend of flowers and who-remembers-what-else that turned our lawn into a mini meadow. Though all that remains are the English daisies (Bellis perennis, which have taken over the entire lawn), the effect is wondrous in spring when the cheery white daisies seem a reflection of the apple blossoms above. We’re happy, the kids and dogs are happy (and healthy), and the bugs and moss are ecstatic.


Speaking of moss: why is it so maligned? Moss is, after all, the Northwest’s native ground cover. It’s soft, it grows in the shade, and it never needs mowing or feeding. If the spot is shady, give up on grass and grow moss (or a nice perennial shade garden). If you insist on killing moss, be aware that iron sulfate and ferrous ammonium sulfate often don’t finish the job and may be lethal to pets that lick it off their paws. And don’t even think about letting the kids out to roll around for a week or two. A safer choice is moss-killing soap, which also can be used on roofs and patios. In the lawn, you must “thatch-out” the dead moss and make the conditions more grass friendly—proper drainage, light, fertilizer, water and mowing—or the moss will return.

Fairy ring

Fairy rings are little crop circles devised by alien mushrooms. All right, the mushrooms aren’t really alien (as far as we know), but they are magical with a concentrically expanding growth pattern and a lifespan of perhaps a hundred years! There’s no good remedy to these persistent fungi, so learn to live with and love them—besides, you don’t want to annoy the fairies.


Clover is another so-called pest that’s actually good for grass. Clover plucks nitrogen directly from the air and fixes it in the soil, providing a natural supplement to expensive fertilizers. And while we’re fixing nitrogen, let’s leave our clippings on the lawn when we mow. Contrary to common belief they don’t create thatch; instead they return up to a quarter of the lawn’s nitrogen requirements.

Weed-and-feed concerns

When it’s time to feed the lawn, think twice before buying that bag of weed-and-feed. The “weed” part of the equation is often the herbicide 2,4-D, which has been linked to lymphatic cancer in dogs and shows evidence of neurotoxicity, lymphoma and reproductive damage in humans. Tracked into the home, 2,4-D may persist for up to a year. According to the National Coalition for Pesticide-free Lawns, of 30 commonly used lawn pesticides 19 are linked with cancer or carcinogenicity, 13 with birth defects, 21 with reproductive effects, 26 with liver or kidney damage, 15 with neurotoxicity, and 11 with disruption of the endocrine (hormonal) system. Every year, 100 million pounds of pesticides are used in homes and gardens by the homeowners themselves, not including those applied by professionals. Makes clover seem pretty attractive, doesn’t it? Organic fertilizer—minus the weed killer—is a far safer choice. Broadleaf weeds such as dandelions can be hand-popped or spot-treated with straight white vinegar on a hot, sunny day. Or live with the dandelions and keep the grass mowed to two inches tall to prevent seedheads.

Crane fly

No discussion of lawn pests would be complete without that boogeyman of the turf, crane fly. Adult crane flies, known colloquially as daddy-long-legs, hover above the lawn in late summer to lay their eggs. Yellow jackets are one good predator of the adults. Crane fly larvae, or leatherjackets, feed on grass crowns. Every year, fear of crane fly causes lawns across western Washington to be doused with insecticide “just in case.” Here’s what the spray companies won’t tell you: crane fly larvae are rarely a serious problem. Treatment is recommended only if they are present in huge numbers—more than 40 per square foot; the vast majority of lawn problems attributed to crane fly have other causes. To monitor leatherjacket populations, cut four 6x6-inch squares of turf in different areas of the lawn in February. Count the larvae in each, multiplying the number by four for the square-foot total. Be aware that treatment for crane fly kills earthworms and many other soil organisms. Stop chasing away the starlings and they’ll eat them (the starlings will eat the crane fly, that is; if it’s the other way around… bring on the chemicals!).

Slime mold

One of the most fascinating of all life forms is the slime mold. Every bit as weird as it sounds, the appearance of this mutant blob in lawn or garden is a real call-the-kids moment. Is it animal? Is it vegetable? Here’s the best part: they move! Yup, like a giant amoeba flowing (very slowly) over the surface to ingest organic matter. Slime molds aren’t true fungi. There are many different forms from delicate cauliflower shapes to those that look like something the dog threw up. They are often brightly colored, like the yellow spongy one that made itself at home in my veggie garden for a short time. Yes, they can be gotten rid of; no, I’m not going to tell you how. Slime molds are harmless and will eventually creep back to the mother ship.

Lawn care: for too many of us it’s like getting up in the morning and taking everything in the medicine cabinet—just in case. Many insecticides and herbicides for the lawn are broad spectrum killers; maybe a lot broader than we know. To be safe, go home and Google the active ingredient of any pesticide before you buy. With tolerance and a little education we can start our own grassroots movement, bringing good health to more than just the lawn.

Grow your own moss

Add equal parts buttermilk and water to a blender. Throw in a big handful of moss and blend well. Pour over the desired area. Keep moist until moss is well established. Moss may need water in dry summers. To see the best of moss as a ground cover, visit the Bloedel Reserve on Bainbridge Island. Reservations are required, call 206-842-7631 or visit


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