Dear Helen: Are motion-activated sprinklers effective at keeping deer out of gardens? I believe I鈥檝e tried just about everything else, with no success at lessening the destruction these animals have visited upon my once lovely garden.
M.D.
I hear they work well in some situations, but in my experience all it takes is just one really determined deer to defeat almost all deterrents. I had one deer repeatedly push aside heavy bricks and logs laid over the bottom of deer netting in order to crawl under the netting and access the garden.
I do remember a wry note from a gardener who had employed motion-activated sprinklers to keep the animals away. The result: 鈥淩eally clean deer鈥� along with numerous and profuse apologies to delivery people.
Dear Helen: My new Christmas cactus plant is full of flowers now, but when the flowers have all faded does the plant need any special care to bring it into bloom again next winter?
M.F.
To prolong the current flowering period for as long as possible, position the plant in bright light and cool room temperatures. Keep the soil just modestly moist.
After the plant finishes blooming, give it a period of rest by cutting back on watering. Give only enough water to keep it from shrivelling.
Gradually resume regular watering early in the spring. The plant will benefit from a summer outdoors in filtered light. Water regularly through the summer, adding a house plant fertilizer to the water, at half the recommended strength, every two weeks. Spray-mist often with plain water. Bring the plant back indoors as night temperatures begin dropping down to 5 C.
If the plant must remain indoors, move it out of hot, direct mid-day and afternoon sunlight to a window facing north or east.
In the latter part of August, stop fertilizing and begin reducing water again to initiate a hardening of the new growth and facilitate its ability to set flower buds.
During this pre-bloom rest period, dry conditions, cool temperatures, and naturally short days will initiate bud set. If possible, place the plant where no artificial light is turned on between dusk and sunrise. Once flower buds have formed, begin watering normally again and resume the conditions recommended for the flowering period.
Dear Helen: I鈥檝e noticed quite a few plants with names ending in 鈥渨ort.鈥� Is there some special meaning or significance to that ending, as in lungwort, liverwort, and of course St. John鈥檚 wort?
W.S.
The suffix 鈥渨ort鈥� was added to the names of plants thought to be useful. Often they were considered to have some medicinal value.
In Medieval times there was a theory that a plant looking like a human body part would be helpful in strengthening or healing that part. That鈥檚 likely how liverwort (Hepatica) and lungwort (Pulmonaria) were given their common names.
St. John鈥檚 wort was named for the plant鈥檚 time of bloom, around St. John鈥檚 feast day on June 24. The plant has been used in herbal medicine since ancient times.
The suffixes 鈥渨ort鈥� and 鈥渨eed鈥� separated plants thought to be useful from those considered useless, or troublesome, like bindweed and knotweed. Now we know that many plants with names ending in 鈥渨eed鈥� are actually useful, like milkweed and pigweed.
Dear Helen: What is a 鈥渢rap鈥� crop?
L.V.
Trap crops are planted to lure insect pests away from main plantings that attract the same pests. They are sacrificial plants used to protect a desired crop.
A commonly used trap plant is nasturtium, an easily grown annual flower with numerous virtues. The leaves are decorative, the flowers brightly coloured. Both the flowers and young leaves are edible. And they attract the black aphids that also infest globe artichoke and broad bean plants.
Nasturtium leaves are also popular egg laying sites of the white cabbage butterfly. The eggs evolve into pale green, velvety caterpillars, the same ones commonly found on cabbage, broccoli and cauliflower. The caterpillars chew holes in the leaves and munch on broccoli and cauliflower florets.
Planted around vegetables vulnerable to infestations of black aphids or cabbage worms, nasturtiums will draw some of the pests away from the vegetables. Radishes are used to attract flea beetles and root flies away from cabbage family vegetables.
Trap crops are commonly located around the border of a main planting. Adding more of the trap crop plants in between rows of the main crop adds further protection. When trap crops become overloaded with a pest they can be removed.
