Dear Helen: For the first few years in our garden, a young cherry tree gave us lovely fruit, but in the last three years the tree has flowered and set fruit that promptly drops off. I keep the tree watered in dry weather.
M.C.
If the tree is the only cherry tree in the garden, and it produced fruit before, I鈥檓 presuming it is a self-pollinating variety; that is, not needing a different variety, one that blooms at the same time, to cross-pollinate its flowers. Most sweet cherry varieties do require a pollinator. Stella, a self-pollinating variety, does not.
When a fruit tree blooms and sets fruit that drops from the tree, something has gone wrong with the pollination process. If a lack of a needed cross-pollinating variety is not the issue and the tree is provided with the moisture and nutrients it needs, the problem commonly lies with the weather.
Wet, windy, cold conditions discourage bee activity. Bees and other flying insects pollinate fruit trees when they carry pollen from bloom to bloom as they feed from the flowers. Nasty weather at bloom time can also affect the quality of the pollen and its ability to move down into the ovary of a flower to complete the fertilization process that leads to successful fruit formation.
We cannot guarantee fine weather conditions as our fruit trees flower in spring, but we can provide flowers to nourish bees. Spring-flowering plants that attract and feed bees include crocus, English daisies, perennial candytuft, Oregon grape, red flowering currant, salal, winter heathers, and kale that has wintered in the garden.
Dear Helen: Our potted hydrangea has become infested with a sticky fungus and some odd fuzzy whitish blobs. What is this, and what can I do about it?
P.J.
The pest on your hydrangea is cottony cushion scale, an insect that feeds on plants by sucking their sap. The mature scales look like mealybugs. Their brownish bodies are covered with a whitish wax. A distinguishing feature is a large, fluted egg sac containing hundreds of eggs.
Scale insects are difficult pests to control, and it is usually recommended to discard heavily infested plants. Sprays affect only immature stages of the pest. Adult scales are protected by their waxy exterior and eggs are hatched under the adult鈥檚 protective shell.
As scales suck sap from a host plant, they excrete large amounts of sticky honeydew on which sooty moulds can grow.
If you choose not to discard the plant, try removing some of the insects. Prune away the most heavily infested stems. Gently scrape remaining stems clean and then wipe them down with soft, damp towelling. Follow the manual cleaning with an insecticidal soap spray (not on a hot day). Repeat the spray monthly to target new generations of immature scale stages.
Dear Helen: My lilac has not bloomed for two years. What can I do?
D.P.
Perhaps the plant needs some rejuvenation. If it is congested or/and overgrown, take out up to a third of the oldest (thickest) stems at ground level and reduce the height of the rest, making cuts right above growth buds or leaves situated directly opposite each other. Do this now.
Clean up under and around the lilac, scratch lime into the area, water deeply and mulch with a nourishing compost. Avoid high-nitrogen fertilizers. Nitrogen, represented by the first number on labels, promotes green growth. The other two numbers, indicating phosphorus and potassium content, are more important for bloom production.
Garden events
Dahlia meeting. The Victoria Dahlia Society will meet on Thursday, June 7, at 7:30 p.m. in The Victorian at Mckenzie, 4000 Douglas St. Topics to be discussed are Insects and Diseases and What鈥檚 up in the Garden. Visitors are welcome.
HCP workshops. The Horticulture Centre of the Pacific, 505 Quayle Rd. in Saanich, is offering the following workshops. To register call 250-479-6162. hcp.ca.
鈥� Plant identification & Culture. The next session in this ongoing, monthly course (can be joined at any time) will be on Saturday, June 16, 1 to 4 p.m. In each session Diane Pierce introduces 25 new plants, with descriptions, preferred growing conditions, landscape uses and maintenance. Cost to HCP members per session is $35, others $45. Cost for 12 sessions: members $350, others $450. To register call 250-479-6162. hcp.ca.
鈥� Making a Stepping Stone: A children's workshop for ages 5 and up. Create a beautiful stone with concrete, gems, shells and hand imprints. All materials are provided. Parents are required to participate. Cost per child is $15.
