In Good Thyme - by Mariana Graham

Q: I'm concerned about my pink pussy willow shrubs. They have woody pods where new branches shoot out from the shrub. The pods have what appear to be air holes on top. Inside each pod is a reddish-orange-colored worm/pupae/bug thing. The bush seems to be healthy. Please, if you can identify this for me I would be so happy. Thank you, Rebecca M. (via e-mail)

A: Before answering this question, I should explain that I sent Rebecca a return e-mail telling her that this would be a tough problem to diagnose without positively identifying the insect. I asked if she wanted me to arrange for what Master Gardeners dub a "hort (horticulture) call", which is free. Rebecca agreed, and veteran Master Gardener Rick Fulgham paid a visit to her garden, where he identified the insect as willow borer. Also known as poplar-and-willow borer, the larvae of this weevil, Cryptorhynchus lapathi, eat away at the limbs of poplar, cottonwood and willow. Just as Rebecca described, the insect is often found in the crotches of limbs, where it will munch through the bark, causing limbs to weaken and break. All willows and poplars are susceptible to the borer, and an occasional alder or birch is affected. In the larval stage, it's a pale c-shaped grub with a reddish-brown head, but when it reaches adulthood, the willow borer is transformed into a beetle that resembles a black and white-mottled leaf, sometimes tinged with pink. The textbook I searched for information on this bug says that the adult willow borer "somewhat resembles bird droppings." Now there's something to aspire to.

As Rebecca observed, the larvae spend the winter in the tunnels or galls she aptly described as pods. The adults spend the winter in fallen leaves and dead vegetation beneath the affected tree or shrub. In the spring, both adults and larvae will start eating new shoots. Telltale signs of willow borer are holes in the lower end of stems, cracks and dead patches on the bark of trunk and branches, often with a sawdust-like substance emerging from them. Rick advised Rebecca to cut away and destroy all affected branches. In the spring, and again in the fall as a preventive measure, she has the option of spraying the shrub with an insecticide containing chlorpyrifos (trade name Dursban). An alternate insecticide (trade name Sevin) contains carbaryl, which has a shorter residual effect on the environment. When using either of these organophosphate chemicals, be sure to follow package directions precisely!

Personally, I would rather do without the type of shrub that attracts the insect than use any chemical at all. As someone who grew up when DDT was considered safe and was sprayed with abandon, I distrust most garden chemicals. They all eventually leach into the groundwater, and I'd prefer not to drink anything that's spelled with more than five letters. Okay, maybe a margarita… Rebecca's willow problem was identified and control options proposed through a WSU-Island County Master Gardener "hort call." You too can request to have a Master Gardener visit to offer solutions to your home garden dilemmas, ranging from insect infestations and plant disease to suggestions on what would do best in your particular garden environment. All of us are volunteers trained through the WSU Cooperative Extension program. And every one of us is passionate about gardening. Call 679-7327 to request a free home hort call.

On a personal note, I'm proud to announce that I've recently been accepted for membership in the Garden Writers Association of America. I'm honored to be part of this organization of respected professionals representing publications such as the Chicago Tribune, The Oregonian, Seattle Post-Intelligencer and Better Homes and Gardens; nurseries and arboreta including Longwood Gardens, New York Botanic Garden, Heronswood and White Flower Farm.

Have you purchased your tickets yet for the annual Whidbey Gardening Workshop? It's scheduled for this Saturday, March 3 from 8 a.m. to 3:30 p.m. at Coupeville Middle School. Fees are $15 in advance ($12 seniors) or $20 at the door. For registration information and a list of classes offered, call Island County WSU Cooperative Extension office, 679-7327, or go to www.island.wsu.edu/wgw.htm.

Do you have a garden question or comment? Is there a topic you'd like to see discussed? Do you have a hint to share with other home gardeners? Please contact me by phone, fax or e-mail, as listed below.

Mariana Graham is a WSU-Island County Master Gardener and a member of the Garden Writers Association of America. Send her your garden questions, hints or comments via the Whidbey News Times, 675-6611; fax 675-2732 or wnt@whidbey.net.

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.