PRAIRIE GARDENER: Blossom thief plagues mystery garden plant

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Female flower

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Male flower

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Q: This plant just grew in my flower garden without any help from me. Does it look like a pumpkin plant to you? I have a problem, though: Something keeps cutting off the blossoms as you can see in the picture. Can you tell me what type of garden pest would cut them off as clean as that? Almost as though they'd been cut with a knife.

I would appreciate any observations.

Thanks, Bob

A: It does indeed look like a pumpkin, zucchini or some other squash plant. You don't say whether there is any trace of the blossoms after being cut off. If the flowers do disappear I would suspect rabbits are eating them. Squash blossoms are a delectable, edible product of the plants and unless you want to build a tall wire-mesh fence around your volunteer squash plant there's not much you can do to deter the bunnies. Or, perhaps a neighbour is sneaking over to harvest the blossoms for fiori di zucchine ripiene -- stuffed zucchini blossoms -- in which case you might want to have a word with them.

If the blossoms remain as evidence however, it's probably just nature taking its course. The male flowers of the squash appear before the female flowers. After a time, they simply fall off, dropping cleanly from their stems as if snipped off. The female flowers stay on for quite some time, even if not pollinated.

You can tell the difference between the male and female flowers. The males usually grow on tall upright stems while the females grow on shorter ones and have a little baby pumpkin bump or swelling underneath the petals at the top of the stem. Many growers remove the males to transfer the pollen to hand-pollinate the females, which is necessary to produce fruit.

Aphids

Q: I have an indoor hibiscus plant that over the past year has been infested with aphids. Not sure where they came from but I have tried almost everything. I have used the "sticky strips," insect soap, as well as dish soap and water. I have rubbed both sides of every leaf as well as the flower buds and the blooms.

The plant still looks healthy and the flowers do still bloom although they are now covered in a ton of "green stuff." My windows and furniture are always covered in aphid droppings and I need help to finally get rid of the problem.Any suggestions?

Thanks, J. Savage

A: Sticky strips are effective for attracting and trapping flying pests such as fungus gnats and whiteflies. Aphids pretty much stay put, sucking the plants' juices, so to speak, and defecating all the while. The trick is to physically remove the aphids from their food source.

Take the plant outside (if you can) and give it a good blast with the hose to knock them off, paying attention to where the aphids congregate. If you can't take the hibiscus outside, you can try doing this in the shower. Follow up with a good insecticidal soap or organic pesticide. A recent phone conversation with a reader revealed her success getting rid of aphids outside using a mixture of powdered milk and water applied as a spray, an eco-safe method usually suggested for treating powdery mildew. I did a bit of research and found others who had some success with this concoction. Repeat your chosen method as often as necessary at least once a week. Each one-week-old adult aphid can produce live young -- 50 to 100-- without having to mate, so a small infestation can grow rapidly in a few weeks. Try an organic method, particularly because your hibiscus is grown as houseplant, and inspect it daily.

Plant problem

Q: I live outside the city and in the last two years there has been a cotton-like substance appearing on flowers in some of my containers. It leaves the plant droopy and of course, dead. I have tried a couple of sprays; one was an insecticide and the other an "all-purpose" type, but obviously they didn't help. I have seen this on other wildflowers, even enveloping some of the mushrooms that abound this year. Any advice you can offer?

Thanks, Erin

A: Wet, cool weather aids in the proliferation of various fungus and mould growth on plants, particularly if there is poor air circulation amongst specimens crowded in containers or garden beds. Remove infected parts of plants and discard. Apply a fungicide to the soil at the end of the season if you are going to grow anything in that spot next year. Drier, sunny weather usually takes care of most mould problems.

Floral emblem of Saskatchewan

Q: I read your column on lilies the other day and have a question. I have a friend in Alberta who is looking for the wild tiger lily. We have lots here with the small dot on them but she wants the wild ones that grew in Saskatchewan that have the large dot. Can you tell me where I can get some seeds?

Gerry

A: I was unable to find a source for seeds, but Prairie Originals in Selkirk offers three-to-four-year-old blooming size plants of the red lily Lilium philadelphicum in their catalogue; phone (204) 785-9799, toll-free 1-866-296-092 or visit www.prairieoriginals.com.

Raspberries

Q: I have a patch of raspberries in full sun that has vigorous foliage growth but no berries. I remember the nursery telling me to cut the plants down to the ground each fall, which I have been doing, and the plants re-grow to about three feet high each year; but now I am wondering if I should not cut them back this year? Over the last few years we have got a handful of berries, but the last two years none at all.

Karlene

A: Since raspberries produce fruit on two-year-old canes, by cutting them back each year you have essentially been removing the fruiting stock. Leave all the canes this year and they should produce berries next year. Then, remove those old canes at the end of harvest, leaving the new canes that emerge next spring and summer. They will be the berry producers for the following year. The best time to prune is after the crop of fruit has been picked. Apply some mushroom manure or compost in early spring or late fall to keep the plants robust.

linda.stilkowski@freepress.mb.ca

Republished from the Winnipeg Free Press print edition August 23, 2009 D9