Alberta Cancer Foundation

Ready your garden for the winter

Although the summer’s blooms have faded, there is plenty of work for a green thumb to do before the snow flies. This means you can still roll up your sleeves and get your hands dirty. It’s time your yard got ready for next year’s spectacular blooming show.

Tips: End-of-season garden clean-up

According to Lisa Gee, greenhouse manager at Calgary’s Blue Grass Nursery, Sod & Garden Centre, the fall is one of the busiest times for gardeners. “It’s busy for cleaning up,” she says. “It is kind of a nice feeling when you have your garden spruced up and ready for planting in the spring.”

Gee says she starts her annual fall cleanup by tidying her perennials. She cuts them down to just above the ground and removes any dead flowers or seed pods.

The critical part is removing rotting vegetation, she explains. “It’s the leaves you have to worry about,” she says, “as they can rot.”

Sandra Smith, an avid gardener whose blooms delight visitors to her central Alberta farmyard, says early fall is also a great time to divide and move many perennials.

She has shared many a plant with neighbours and friends in this way. In fact, some of her most prolific bloomers are heirloom varieties of roses, lilies, delphiniums and more that have travelled with her as she moved all over the province during her 46 years of marriage.

“There are lots of flowers from old friends in my garden,” Smith says, a former home care worker. “There are memories of people who are gone.”

Smith says many of her perennials don’t require extra care. But those that do get a mulch treatment right after the first hard frost, which varies throughout the province, but generally occurs in September or early October.

It’s advice Gee also gives gardeners. She recommends people begin covering their tender perennials in organic mulch, such as straw, fallen leaves raked from the lawn or even grass clippings. The mulch will act as insulation, bettering the chance of those plants that may not survive the winter. This is very important for rose bushes that often require extra protection to survive.

Gee also advises once the first snow flies, it can be piled on top of plants for extra protection. “It’s kind of like a little igloo,” Gee says, adding expert gardeners can sometimes push the limits of their garden zones in this way.

Potted perennials should be buried in the soil up to the container’s lip, or pulled out and planted to avoid freezing. Planters just don’t offer enough protection for the harsh Alberta winters.

The first hard frost is also an optimal time to wrap conifers, such as cedars, to keep them from getting dried out and suffering die-back. This is an especially important task in the southern part of the province, where chinooks can decimate evergreens.

“Burlap works well,” Gee says, adding that wrapping too soon can lead to the needles singeing.

Leg warmers for your trees, as Gee calls them, are the plastic wraps you can purchase at most garden centres for covering tree trunk bottoms, stopping gophers, rabbits and mice from nibbling on the tree’s bark. This is something that can cause severe damage during the winter.

Lawns also need special treatment as the growing season ends. In fact, preparing your grass for the long, cold winter should start in mid-summer when lawns should no longer be given fertilizer to promote green growth. “In late September or early October, feed with fall fertilizer,” Gee says. “It promotes root growth so you have healthy roots.”

Perennial grasses, such as fescues, are hardy and can be left as is to offer diversity and interest in the winter landscape. Tender bulbs must be dug up and brought indoors or they will freeze and turn to mush, Gee notes.

Dahlias should be dug up, sprinkled with a fungicidal powder and kept in a breathable container, such as a paper bag, in a cold, dark room. Gee suggests a root cellar between 5°C and 10°C.

Gladiolas can be hung to dry and then stored in a cold, dark place. Callas also must be brought inside for the winter. “I shake the dirt out and put them in a cool place,” Gee says. They must be kept from completely drying out over the winter.

The alternative is to treat tender bulbs as an annual, replanting them every year. Hardy, spring-flowering bulbs such as tulips, daffodils, hyacinths and crocuses must be planted in the fall. Gee likes to do it near the end of September. “That’s your last step after you do your cleanup,” she says, adding it is one of her favourite tasks as she imagines how their cheery blooms will brighten up the garden in the spring.

Like grass, fertilizing perennials and trees should be discontinued as the summer progresses. Gee says she stops fertilizing her flowers in August to avoid winter kill from under-developed roots.

Another step that is often missed is a good watering of trees and perennials in the fall. “Deep water, with tree spikes if possible,” Gee says.

Crystal Bazar, an arbourist with the City of Airdrie, agrees. “Most trees suffer winter kill because of a lack of moisture,” she says, explaining it is sometimes even necessary to water in mid-winter in southern Alberta when chinook winds melt the snow and raise temperatures.

For those with vegetable gardens, fall is a good time to spread manure or compost, Smith says. She also likes to do a final tilling to eradicate as many weeds as possible before spring comes again.

Readying your garden for winter may seem a chore, but it is worth it, Smith says, who likes to imagine sharing next year’s blooms as she puts her garden to bed for the winter.

“There is enjoyment and beauty in gardening,” she says. “Flowers are uplifting and they are also to be shared. It takes a lot of hours, but it makes it special, too.”