Digging into gardening myths
In gardening, there is always tension between lore and science. We hear about it all the time.
One person will challenge something that we say based on what they learned at the knee of their grandmother, or lore. Another will question us based on what they know of science.
We have respect for all second opinions, regardless whether they are grounded in science or anecdotes.
One person who has dedicated a lot of time to dispelling the persistent myths of gardening is Guelph writer and master gardener Robert Pavlis. He was trained in chemistry and biochemistry, and gardened for over 30 years before selling his software business to focus more on his gardening passion. Today, he applies his scientific mind to chal- lenging garden myths through academic research and trial in his five-acre private garden, called Aspen Grove Gardens, with more than 3,000 perennials. He writes about his findings on his website gardenmyths.com and in his recent book, Garden Myths: Learn the truth behind urban legends and horticultural mysteries.
Ben sat down with Robert to discuss some of the myths he tackles. Make your Christmas tree go the distance: We agree that there is nothing like a real Christmas tree. We run into a lot of lore where tree preservation is concerned.
People have tried to prolong cut-tree freshness using tree preservatives, molasses, sugar, bleach, soft drinks, aspirin, honey and fertilizer. Pavlis puts it bluntly: “None of these products work. Testing has shown that none of these additives work better than just plain old water.”
So what can you do to make your tree last as long as possible — other than just adding water? Pavlis says: “Make a fresh cut when you set it up and get it in water right away. Do not remove any of the bark. Don’t let the tree dry out. Keep the tree away from fireplaces, heat vents and other warm areas.”
Does cutting the tree on an angle, to maximize the amount of wood available for water uptake help at all? “No,” says Pavlis. “Cutting on an angle will do nothing to improve water uptake. In fact, an angled cut runs the risk of being exposed when the water level drops — which will actually make the tree dry out faster.” Noted: keep the bottom cut perpendicular.
Are poinsettias really extremely poisonous? “No,” Pavlis says, “you would have to eat an entire plant to even get a stomachache. So, would a cat or a dog.
“The poinsettia is a Euphorbia, a genus of plants that have a white milky sap. Some people do have an allergic reaction to the sap when they get it on their skin, and it is very likely to irritate the mouth.”
We didn’t ask if it was worth allergy testing the dog. How can I bring my Christmas cactus into full bloom for the holidays?
We’ve heard of people locking their Christmas cactuses in dark closets for 12 hours every night to try and maximize blooms. Says Pavlis? “Myth.” Let the cactus be free! “A dark period of 12 hours will help, but they don’t need total darkness.” And 12 hours, let us point out, happens to be the length of night right around Christmas.
Pavlis adds: “The first thing to realize is that the most common Christmas cactus sold is a mislabelled Thanksgiving cactus ( Schlumbergera truncate) which blooms in midfall. The Christmas cactus ( Schlumbergera x buckleyi) blooms right around Christmas. These are approximate bloom times and, in the home, they bloom when they get the conditions they need.”
The trick, then, is to make sure those conditions are met.
“The most critical requirement for setting buds is low temperatures. The typical cool fall temperatures work well. Leave them near a window or in a cool porch for six weeks and they will set buds. Letting them dry out between watering will also encourage the development of buds,” Pavlis says.
So, please accept our gift: some scientific support for best practices as you meet with relatives during the holiday season.
And if that’s not enough, consider buying the book: Garden Myths, by Robert Pavlis, CreateSpace Independent Publishing, $20.