Gardening
A tension between lore and science.
In gardening, there is always a 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 (lore). Another will question our “authority” based on science.
We have respect for all second opinions, regardless of 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 Robert Pavlis. Pavlis 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 challenging garden myths through academic research and trial in his six-acre private garden of over 3,000 perennials. He writes about his findings on his website www.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 these myths.
Make your Christmas tree
go the distance
We agree that there is nothing like a real Christmas tree. We run into 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
Robert Pavlis
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? According to Pavlis, “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 fire places, 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? Over to Pavlis, “No, 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 it perpendicular.
Are poinsettias poisonous?
“No”, says Pavlis, “you would have to eat an entire plant to even get a stomach ache. 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 maximize the bloom of my Christmas cactus in time
for Christmas?
We have heard of people locking their Christmas cactus in a dark closet for 12 hours every night to try and maximize blooms.
Pavlis? “Myth.”
Let the cactus be free!
“A dark period of 12 hours will help, but they don’t need total darkness.”, which happens to be about the length of night around Christmas.
He adds, “The first thing to realize is that the most common Christmas cactus sold is a mislabeled Thanksgiving cactus (Schlumbergera truncate) which blooms in mid fall. 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 cool porch for 6 weeks and they will set buds.
Letting them dry out between watering will also encourage the development of buds”, Pavlis says.
So, let that be a 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
ISBN: 978-1542465229 Publisher: CreateSpace Independent Publishing
Price: $20
Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourthgeneration urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen. com, @markcullengardening, on Facebook and bi-weekly on Global TV’s National Morning Show.