Published in Caledon Living, Autumn 2006:
     “Fall is the best time to garden,” declares David Warburton, owner of Plantsmen of Hockley Valley. “The conditions are best for planting, with cool nights and sustained rainfall. Most plants are through their reproductive duties and they can just establish themselves. This means they will perform better next year. It’s a real window of opportunity.”
     Warburton provides complete landscaping and gardening services, including consulting, design, installation and maintenance. His company specializes in country estates.
     “I’m spoiled here with large properties,” he confides. “I can do orchards, bog gardens, herb gardens. It really stretches me as a designer. Ornamental kitchen gardens are my favourite. Growing cabbages and roses together. When you mix these kinds of plants together it’s companion planting to the nth degree. Predatory insects have a hard time finding the plants to eat.”
     The concept of working with plants’ own tendencies seems to be central to Warburton’s whole approach to gardening. Another reason to work on the garden in the fall is because you’ve seen how plants have performed, and you can make improvements.
     “It’s a great time to plan,” he says. “You can move things around.” He points out that late-blooming plants and grasses are best moved in the spring, but that spring or summer bloomers can be moved in fall.
     He advises finding gentle micro climates for tender plants. The sheltered side of the house is one. Warburton thinks nothing of moving plants five to 10 times, until a good place is found for them.
     “Think of tender plants as having a suitcase handle on them,” he says with a smile.
Dividing
     Fall is also a good time to divide spring and summer blooming perennials that haven’t done as well as in previous years. Daylilies can do better when given more room. Irises that have spread out from a dead centre should also be renewed. Warburton recommends discarding the old, dried-out parts of the plant, and replanting only the vigorous, healthy plants.
     “Smaller parts grow better than old, big parts,” he says.
Storing
     Flowers like dahlias, canna lilies, gladioli, begonias and some salvias, should be dug up in the fall and carefully stored in a cool, dark place over winter, as there’s a tendency for them to dry out. They should be placed in slightly damp peat moss.  Warburton says they should be checked through the winter and may need to be rehydrated. They can be cut back as they die down.
Cutting Back
     This can be the major maintenance work in a garden, and the question is whether to cut plants back now or leave them until the spring. Some plants, including dogwoods and grasses, provide wonderful winter interest and food for birds. Coneflowers, sunflowers, black-eyed Susans and hostas are all favourites of seed-loving birds. Cutting in fall can remove some diseased materials, but some beneficial insects lay eggs in the fall.
     For Warburton, it’s a less hurried time in the fall, so his employees trim then, except for plants with good form and appeal through the winter.
     “It’s an individual decision,” he adds.
     Plant stalks trap snow, and snow is the best insulator for a garden, so Warburton advises cutting back at a much higher level in an exposed garden. “And never cut back lower than five or six inches,” he warns.
     He shakes his head at people who trim their gardens too early. “Don’t cut back everything by mid October,” he says. “As long as plants are green, they’re photosynthesizing and growing, preparing for next year.”
     When plants are fully dormant, they turn yellow and die back or turn to mush. They die back at different times. It’s a good idea to wait for a couple of killing frosts to make sure they’re fully dormant. If you cut back too soon, when they’re still green, they won’t perform as well next year. You could even be killing your plants.
     An exception is Shasta daisies and gaillardias, which Warburton says should be cut back in early fall, even with some flowers on them, so they have time to store energy in their roots. If allowed to flower until frost they might exhaust themselves and fail to flower next year. Marginally hardy plants like Monchs asters and chrysanthemums should also not be cut back if you want them to have a better chance of surviving the winter.
     Similarly, Warburton explains that there’s no point in cutting back shrubs like butterfly bush and roses until the spring, because they have to be cut back to live wood. Cutting them back in the fall can cause further die back during the winter. Also, lavenders, heathers, heaths and thymes are better left for the spring clean up.
Feeding
     Fertilizing beds is recommended, but not with nitrogen. High potassium or a complete mineral fertilizer will feed plants, breaking down over the winter, ready for assimilation in the spring. Mulching plants with straw around the roots helps protect them.
     Warburton warns against raking leaves onto beds. Most leaves mat down too heavily. Oak leaves are fine, as they keep their shape better and form less of a wet, heavy carpet. Covering beds with evergreen branches, their ends shoved into the earth, is better.
Trees
     Fall is the best time to plant trees, because it is usually wet, with no damaging heat to stress them.
     “A nice prolonged, warm fall has the ideal conditions for trees to put down roots,” Warburton points out.
     Exceptions are big fruit trees, which never transplant well, and evergreens, which, in the late fall, won’t get their roots established before the dryness of cold winters sets in. It is better to plant evergreens in the spring.
     All young trees, but especially fruit trees, should be protected from hungry rabbits, mice and voles, with open plastic tree wrap. Wraps should be removed mid spring to prevent insects from sheltering under them. Wrap can also protect trees from sun scald, when the hot March sun, followed by a night of freezing, can cause the bark to split and injure the tree.
     The rather delicate shrub, Daphne, should have its branches tied tightly to the trunk well before the first snowfall. Heavy snow can tear its branches apart.
Evergreens
     It may be surprising to learn that evergreens, which seem so hardy in the coldest climates, risk winter desiccation, or drying out.
     “What’s really important with all evergreens is to soak them going into winter,” Warburton emphasizes. “Water, water, water them. You can even water them during thaws in winter.”
     Ornamental cedars and upright junipers should have their branches wrapped around the trunk with open plastic wrap or twine, to prevent branches from breaking under snow load. Collections of conifers should have a perimeter fence of burlap on the windward side. Dwarf Alberta spruce should be double wrapped with burlap to prevent burning.
     After snow falls heavily on evergreens, it can be gently knocked off after the storm with a rake or broom. This can prevent damage.
Lawns
     Noting that he’s putting fewer pure grass lawns around people’s houses, Warburton mentions the growing appeal of mixed lawns that include such low growers as clover, fescue and wildflowers. Some of these “fields” of low growth need to be mowed only once or twice a year.
     Regular lawns can be mowed less often in the fall, and with blades set higher, so as not to scalp the grass. Yet don’t leave grass too long. “Shag promotes fungus,” warns Warburton.
     It’s a good idea to rake lawns free of heavy leaves, which can smother the grass.
Roses
     All but the hardiest of roses need to be mounded for winter with a cone of soil that’s six inches tall at the base of the stem. Be sure to use soil, not straw or other materials, because it needs to be a dense cover. Warburton even suggests shaking the canes to drive out air pockets.
     Climbers, except for some of the Explorers, need to have their canes laid down and covered with soil. The same advice holds for Ramblers which flower on old wood. This should be done after frost, when the roses have lost their leaves and are fully dormant. Also, by that time mice and voles will have found winter homes elsewhere.
     There are old-fashioned roses that are hardy without winter protection. Many roses and tender plants should be covered to provide them with stable temperatures. Fluctuations in temperature can be more dangerous to plants, causing them to freeze. Protection also keeps rose canes from drying out due to sun and wind.
Rhododendrons
     Along with magnolias, azaleas and rhododendrons should be fed a fertilizer “liquid sunshine” to harden them and help them set many more buds for next year. They should be “watered like mad,” then mulched with straw around the roots. Rhododendrons are actually evergreens, and continue to breathe all winter. If their roots freeze, they can’t take in water and they will dry out. For this reason, Warburton explains that they need to be protected from sun and wind, both of which can dry the plant. It’s also good to spray them first with an anti-desiccant like Wilt-Pruf.
     Before the ground freezes hard, making it difficult to pound in stakes, Warburton suggests putting a framework of stakes around the plants in preparation for attaching a burlap coat. After the hard frosts, shelter with burlap, making sure it doesn’t touch the plant. Put straw inside, heavily over the root zone, and cover the top to close out the light.
     While rhododendrons are vulnerable, there are some which grow well in this area. Warburton says there are 10 to 12 Finnish varieties that are hardy to minus 25 degrees.
     According to Warburton, 90 per cent of plant problems are related to their soil.
     “Winters are hard on plants,” he says. “You have to give them the best conditions in the soil to survive on.” In the case of rhododendrons, they need rotting soil that includes such acidic materials as compost and chunky peat.
     While these are all useful techniques, they need not be rigidly followed.
     “I take the Greek view that there is a spirit in every plant,” says Warburton. “If you pay attention, the garden instructs you on what it needs. Imposing your schedule on it produces a mediocre garden. This attitude changes the whole nature of a garden. Working in it becomes less of a chore than a form of meditation. You’re really responding to the garden.”
     Warburton continues. “I always tell my workers to check their energy before gardening. It’s better to be calm and reflective. I believe that was one of the purposes of the garden gate. It forces you to stop for a moment before entering. This is a better way to approach things, and will give you more success.”
By Gloria Hildebrandt