Teacher says: Fall brings new starts with plants

File photo. File photo.

The autumn equinox brings a change of season. Regardless of drought, derecho or whether we believe fossil fuels contribute to global warming, at 10:49 am EDT on September 22, Earth faces the sun straight on before tilting toward fall. Like students at the start of the school year, gardeners can begin a brand new schedule and buy new stuff. And maybe start all over again. Perhaps the garden will forget who we were last semester.

Things generally get out of hand out here in the hollow by late summer, and I think about all the things I should have done last winter when the snakes were hibernating and you could see what you were doing. Sometimes it’s best to wait another month or so for a killing frost before tackling the worst overgrown areas. But if you have a problem with woody invasives (see list below), now’s the time to strike.

Because plants respond to shorter day lengths by sucking down nutrients to store in their roots, this is an ideal time to poison them. Conscientious gardeners rightly suspect any use of chemical herbicide, but I know many a naturalist (including the New England Wild Flower Society, Doug Tallamy and Phil Stokes) who has turned to glyphosphate (the generic chemical in such weed killers as Round-Up) for one-time assaults on troublesome invasives.

The trick for woody plants is the cut and paint technique, which avoids the problem of drifting spray and overkill from pumped-up canisters or backpacks, and gets the job done with one small controlled application. Mix a 50-50 solution of a glyphosphate-type herbicide and water in a plastic bucket or hand-held spray bottle (buy small amounts so you don’t have to store leftovers long). Cut the doomed woody stem to the ground and paint or spritz the fresh cut (before it’s had time to dry) with a swipe or squirt of the deadly mix, all the way to the edge of the outward cambium circle. Wear plastic gloves, don’t touch your face or eyes and wash up with soap and warm water.

Those of us who have some moisture in the ground might consider a bit of planting and moving about. Although most established perennials prefer being transplanted in early spring, fall is the best time to divide those with extensive fleshy roots like peonies, oriental poppies and Siberian iris. All are long-lived tough plants that resent disturbance and take a few seasons to recover, but if peonies or poppies have become shaded, or an iris clump too big for its space, now’s the time to take fork and spade in hand.

Amend soil with compost and/or rotted leaves—no high nitrogen fertilizer to encourage leafy growth—and muddy in with a good soak. Plant peonies shallow, with just an inch or two of soil over the eyes, or growing points, on the surface of the large pale pink fist-shaped roots. The chief reasons for poor bloom in peonies are lack of sun and planting too deep.

Make a foray to the garden centers and hardware stores to cap off the season and keep the local economy going. Get cracking. We have three months ’til the planets signal winter and another term begins.

Cathy Clary is a gardening teacher and consultant; she tends ornamental beds and a kitchen and cutting garden at home in a hollow south of Charlottesville. Read more about her at hollowgarden.com, and e-mail her with questions at garden@c-ville.com.