Dear Helen: Because they were among my father’s favourite flowers, I treasure the dahlias in my garden. My problem is that my plants always end up with abnormally short flower stems that are covered in black aphids. I realize I’ve not been very vigilant about dealing with the aphids, but that still leaves me wondering why the flower stems are stunted.
My father loved dahlias too. I remember clearly the flower-filled row of Park Princess plants that he grew along one edge of the vegetable plot in my parents’ Lochside Drive garden. Park Princess is a low-growing bedding dahlia that Ferncliff Gardens, a dahlia specialist in Mission, describes as “one of the best.” The flowers are bright pink.
Aphids suck the life-giving sap from plant tissues, causing distortion in leaves and shoots. Water sprays, if applied every few days, can be an effective control.
More serious is a mosaic virus that is spread by aphids. Infected plants can display a variety of symptoms that include distorted foliage that is often discoloured. The infection can also cause general stunting and short flower stems.
The virus survives over the winter in the tuberous roots and surrounding soil. Mosaic-infected dahlias should be removed and not composted. Clean away any surrounding weeds.
It is possible, if there are no other symptoms apart from the abbreviated flower stems, that aphid feeding alone is the cause, but if the virus is present it is best to remove all infected plants and their roots from the garden.
If you choose to grow replacement dahlias next year, buy the tuberous roots or young, potted plants from a reputable source and choose a location in a different area from the current location of your dahlias.
Next spring, monitor the developing plants carefully and keep them washed clear of aphids. Avoid over-watering and over-fertilizing with nitrogen. Both foster soft, often weak and disease-prone growth that also attracts aphids.
Dear Helen: I see that I’ve left some of my pole and runner beans to develop past their prime. Seeds within the pods have begun to swell. Once that happens, at least in my experience, the pods become tough and unappealing. What’s the best course of action now? I dislike ever wasting food, but are the overgrown, bulging pods good only for composting
Plants or plant parts used to make compost are not wasted. They decompose to become the organic matter that, when applied to garden plots, helps to create a living, healthy soil.
As for the over-developed bean pods, they hold a special treat for you in the form of fresh “shell” beans — young beans within the pods harvested when plump, steamed lightly until tender, and served with butter and salt. They are delicious.
Picnic in the gardens. The Horticulture Centre of the Pacific, 505 Quayle Rd. in Saanich, invites families and friends to bring their own dinners for a picnic in the gardens this evening. Enjoy local musicians, browse through the works of local arts vendors, visit a master gardener booth for answers to gardening questions, and check out sales of plants propagated from the gardens. Admission is by donation between 5 and 8 p.m. hcp.ca.
Government House plants. Plant sales every Tuesday and Thursday from 9 a.m. to 12 p.m. at Government House, 1401 Rockland Ave. in Victoria, include an extensive range of plants for sun and shade at the Plant Nursery opposite the Tea Room. Among the many choices are the golden Choisya ‘Sundance’, feathery astilbes, small red Japanese maples, tough and showy heucheras (coral bells) as well as salvias, phlox, sedums and much more. Last sale day is Aug. 27.
Dahlia show. The Victoria Dahlia Society is hosting its 73rd Annual Show on Saturday, 1 to 4 p.m., and Sunday, 11 a.m. to 4 p.m., in Prospect Lake Community Hall, 5358 Sparton Rd. The show will feature hundreds of blooms on display and cut dahlias for sale. Admission is free.
View Royal meeting. The View Royal Garden Club is celebrating its 70th year with a special event featuring Linda Gilkeson, local entomologist and educator, speaking on resilient gardens in the presence of climate change on Wednesday, Aug. 28, at 7:30 p.m. in Wheely Hall, 500 Admirals Rd. in Esquimalt. The evening will include a judged mini-show and a plant sale. Space is limited. Advance tickets for the event are available for $10 at all GardenWorks Centres.