In Good Thyme - by Mariana Graham

Last year about this time the Washington State University Cooperative Extension Office got a call from a South Whidbey homeowner asking for help identifying a plant that had mysteriously come up in the yard of his newly purchased home. He and his wife raised pygmy goats and wanted to make sure it was safe for them. They brought a sample to the Extension office in Coupeville, where an Island County Master Gardener correctly identified the mystery plant as rhubarb. Apparently there had been a vegetable garden on the site at one time and the long-lived rhubarb returned, year after year. It's a good thing the homeowner was suspicious. The red-stalked plant we associate with delicious pies and sweet-tart sauces can also be a deadly poison to grazing livestock and curious toddlers.

The stalks are edible and loaded with vitamins A and C. The leaves, however, contain levels of oxalic acid that are toxic when ingested in large amounts, either raw or cooked. It's not likely that anyone (except perhaps a pygmy goat) would eat large quantities of rhubarb leaves, but it's a good idea to take some precautions when growing rhubarb. Trim leaves from the stalks immediately upon harvesting. Wash the stalks well before cooking. Don't use mushy, frost bitten stalks, where oxalic acid crystals may concentrate. Don't allow grazing animals or unsupervised small children in the rhubarb patch. Rhubarb is a cool season perennial vegetable that thrives in the Pacific Northwest. In fact, Washington State is the largest commercial producer of rhubarb, followed by Oregon and Michigan. It requires temperatures below 40 degrees Fahrenheit to stimulate development of new buds on the buried crown. As temperatures climb, the wide, frilled leaves burst from the earth and rise on firm, ruby-colored stalks.For rhubarb lovers, these stalks are the season's first harvest. Often paired with strawberries and apples, tangy rhubarb is aptly known as "pie plant" in some parts of the country.

While the productive life of the plant is officially listed as eight to 15 years, many a country gardener knows that the hardy rhubarb can live happily for up to 20 years. My husband and I have lived on our rural acreage for more than 15 years. Every year, a renegade rhubarb springs up amidst the wild grasses of what is now a fallow field. I do nothing to care for this wildling but it always cheers me to see it, as much a messenger of spring as daffodils and hummingbirds. Of course, a serious rhubarb gardener would not let her plant languish among the weeds!

Now is the right time to start rhubarb plants from rhizomes (roots) available at some nurseries, or from a fellow gardener who is willing to divide a clump for you. Like most vegetables, rhubarb prefers a sunny location and well draining soil. Dig a wide planting hole and cultivate into it generous helpings of composted manure and organic fertilizer. Find the protruding crown bud on each rhizome and place it no more than an inch or two beneath the surface. Tuck the soil firmly around the buds and water well. Space your plantings about three feet apart, as a mature rhubarb can grow to four feet in diameter. Don't expect to be eating rhubarb pie next spring, however. The plant needs time to build up strong stalks, so wait until the second spring to harvest. Then you can sever the stalks at the soil line all at once, or cut them individually as needed. Don't worry about composting the toxic leaves. The oxalic acid in the leaves decomposes rapidly and will not contaminate the rest of the compost pile. Rhubarb is relatively pest and disease free and easy to maintain. The biggest problem - crown rot -- occurs when it's planted in poorly draining soil. If that's all you have, consider growing in a raised bed. If flower stalks appear, cut them off, as they sap the plant's strength.

Rhubarb responds well to regular watering and fertilization. When you notice spring growth, sprinkle about a cup of 10-10-10 fertilizer around each plant, cultivate it in and water well. In late fall, apply more compost around each plant, but don't cover the crowns or rot may set in. After the first hard frost, cut off any remaining stalks and compost them. Then count the days until spring and dream of that rhubarb pie! For more information on rhubarb than you will ever need to know, check out "The Rhubarb Compendium." You'll find it at www.rhubarbinfo.com.

Garden questions or comments? Call 675-6611; fax 675-2732, or wnt@whidbey.net. Mariana Graham is an Island County Master Gardener and member, Garden Writers Association of America.

MASTER GARDENER CLINICS (click on picture)
Master Gardener plant clinics are being held at various Island locations throughout the summer. On the North end, bring questions and plant samples to The Greenhouse Nursery each Saturday in July from 9 a.m. to noon, Cenex on Aug. 4 from 10 a.m. to 2 p.m. or the Navy Exchange Garden Shop June 30th from 10 a.m. to 2 p.m. In Central Whidbey, it's at the Coupeville Farmers Market each Saturday through the end of July from 10 a.m. to 2 p.m. South end clinics include Freeland Ace Hardware from 10 a.m. to 2 p.m. on June 23, July 28, Aug. 25 and Sept. 22. You can also find Master Gardeners at South Whidbey Tilth on July 7, Aug. 4, and Sept. 1 from 10 a.m. until 1 p.m. Clinics are held at Bayview Farm and Garden June 30th, July 7, 14, 21, 28; Aug. 4, 11, 18 and 25. Clinics may be scheduled at other locations when volunteers and resource materials are available. 'Can't make it to a plant clinic? Call the Master Gardener hotline (360) 679-7327 each Monday from 10 a.m. to 2 p.m. through the end of September.