What to do this week: You can plant spring bulbs until Christmas. Prune or plant trees and shrubs after they have lost their leaves, but wait until spring to plant evergreens. Enjoy the remaining few perfect fall days! But it is OK if you don’t finish cleaning up the garden until spring. That messiness provides winter food and shelter for birds. If you have a stand of Japanese knotweed, wait until the end of the winter to cut it down and then bag it for incineration, because any piece of living stalk or root can start a new colony, even in your compost pile. If you have it, don’t bother trying to kill it, which is almost impossible to do. Just don’t spread it around.
Q. There seem to be divided opinions on raking up leaves versus leaving them in the garden over the winter. What do you recommend? Some people think they provide hiding places for mice and rats; others say they are good for the garden.
A. I think leaves belong in the garden, not in bags. They feed and help insulate plant roots from temperature fluctuations. I think the invention of leaf blowers has made people crazy trying to eliminate every fallen leaf. They are doing more harm than good. We do not use a gasoline-powered blower here, as these are incredibly noisy and polluting. Two-stoke gas engines have been phased out in Delhi, India, yet they are virtually unregulated in American backyards. That’s because lobbyists for the lawn care industry procured US federal protection for them even though they emit formaldehyde and produce nearly 300 times more air pollutants than a pickup: carcinogenic poison, climate-changing emissions, AND ear-splitting noise! I would rather have a few voles in my garden. So ask your lawn crew to invest in electric machines or else just reduce the size of your lawn to help save the planet. Of course, leaves should not be left whole on lawns, so we use a mulching mower with two blades instead of one to cut grass and leaves into smaller pieces that can stay on the lawn without smothering it. The pieces are too small to create thatch or hide rodents and soon become organic fertilizer. To mow leaves, we remove the leaf-catcher attachment and set the blades to mow low. You can also buy a mulching attachment for a regular mower. We rake leaves on the driveway and hard surfaces into a grassy corner, which we mow. We use it later as a nutritious weed-free mulch.
Q. I bought a clematis in June. Will it bloom next spring?
A. Maybe, but don’t hold your breath. There are many different species of clematis with a range of habits. The popular large-flowered clematis have gorgeous blooms, but they can be fussy and slow-growing, sometimes requiring six years to put on a show. And after this long wait, they can wilt and die for no apparent reason. I prefer faster-growing, tougher clematis with smaller flowers, though I avoid the rampant clematis species with sheets of tiny white flowers. Too tough! My favorite clematis viticella variety, ‘Madame Julia Correvon,’ has a half-dozen deep-red 4-inch stars blooming as I write this in mid-November and has been blooming off and on since July. My second best-performing clematis is ‘Betty Corning,’ another small-flowered clematis of viticella descent, which has hundreds of dangling lavender bells throughout the summer.
■ On Nov. 4, I attended the Massachusetts Horticultural Society’s 119th Honorary Medals Dinner at its Elm Bank headquarters in Wellesley. (The garden will reopen Nov. 26 to Dec. 19 for the annual Festival of Trees, featuring indoor and outdoor holiday decorations and model train displays. Visit MassHort.org for more information.) At the dinner, Robert A. Bartlett Jr., chairman of Bartlett Tree Experts, received the society’s highest award, the George Robert White Medal of Honor. Gold medals were presented to Arnold Arboretum director Ned Friedman for his public outreach and his innovative digital output, as well as to society volunteers John A. Cronin, Penni Jenkins, and Heidi Kost-Gross and to past president Katherine K. Macdonald. The silver medalists were Arnold Arboretum curator Michael S. Dosmann and society volunteers Sarah B. Cummer, Kathi D. Gariepy, and Rosalind L. Hunnewell. The Jackson Dawson Memorial Medal was awarded to Thomas G. Ranney in recognition of his plant research programs. Steve Castorani and Mark Sellew jointly received the Thomas Roland Medal for skill in horticulture.
■ This is my last garden column this year, so I will not be answering your questions until spring. Please stay safe, and feel free to feed the birds!