Getting ready for Winter
We’d like to thank the Calgary Horticultural Society for providing us with the information on preparing our gardens for the winter.
Gardening in the chinook zone is challenging. Taking time in the fall to prepare your garden for our variable winter weather and getting a head start on spring garden chores is worth the effort. Besides, it’s nice to be outside during those beautiful fall days.
Tidy, but not Too Tidy
Before the ground freezes, lift potatoes. Dry them in a dark room or covered with a cloth for a day or two. Brush the excess soil off, then store the potatoes in a cool, dark place. Pull carrots, remove the foliage, wash, and place in vegetable bags to store in the vegetable bin in the refrigerator. Carrots will keep in the fridge for months. They can also be stored in the ground if they are covered thickly with a straw mulch to prevent freezing. When you want to harvest these carrots, push the mulch to the side to pull what you want, then cover them again.
If you have harvested all your vegetables, add a layer of compost (2 to 3 cm) on top of your vegetable garden. By spring, the worms and other garden critters will have worked it into the soil for you. Do not leave the soil bare. If you don’t have compost, you can plant a cover crop such as clover or annual rye grass as a green manure that is worked into the soil about a month before you are to plant in the spring.
Lift Tender Bulbs and Annual Geraniums
Lift summer blooming bulbs such as gladiolas and dahlias, which are not hardy here, and store indoors. Let the soil dry, brush it off, place them in a container with peat moss or vermiculite to prevent them from drying out, and store the bulbs in a cool, dry place.
The geraniums (Pelargoniums) we treat as annuals, can be overwintered indoors as house plants or stored. Take cuttings or bring them in before there is a hard frost. If you want to store them, place the plants in a cardboard box like logs, then place the box in a cool, dark room. At the end of January, plant the geraniums in pots for a head start on next summer’s display.
Water shrubs and trees around the drip line on a regular basis, right until freeze-up, to protect their roots from drying out during long, windy, dry winter spells. Use a slow trickle of water over a long period, so the water soaks into the ground. Watering will be very important this fall, after our warm, dry summer. Perennials should also be watered, especially evergreen ones, until the ground freezes. Pay special attention to any plants in beds close to the house foundation and other dry areas.
Pull up all annuals, roots and all, or snip them at ground level and leave their root balls to decompose in the soil. Trim perennials as they fade, leaving at least 10 cm of stalk to trap leaves and snow for winter protection. You may wish to leave some plants intact to provide winter interest in the garden, for example, alliums, coneflowers, sunflowers, sea hollies, and ornamental grasses. These stalks will have to be cut back in the spring before the tender new shoots emerge. Place all garden refuse in the compost bin, except for diseased or mildewed plants. Be sure to cut back peony foliage in the fall to prevent botrytis.
Provide Habitat for Beneficial Insects
If you want ladybugs in your yard next spring to combat aphids that thrive on the tender new growth of shrubs, then you need to provide overwintering habitat. Leave piles of dry leaves and sticks in a corner of the garden. It can be put in the compost bin in the spring, after the herbaceous perennials are up.
Late September to early October is garlic planting time. Plant garlic cloves basal plate down, point up. The tip of the clove should be at least 10 cm below the surface of the soil. The cloves should be spaced about 30 cm apart. After planting water lightly, then cover with leaves or a light-textured mulch.
Plant Spring Flowering Bulbs
Spring starts in the fall! Plant spring flowering bulbs such as alliums, tulips, daffodils, grape hyacinths, snowdrops, Siberian squill, and Glory of the Snow (the Society's Bulb of the Year for 2021). Plant smaller bulbs in drifts or groups of 20 or more. Plant large bulbs such as tulips in groups of at least five. Placing mulch over newly planted bulbs can help keep them hidden from squirrels, who like to dig up what has just been planted. If you have deer in your yard, then tulips are not recommended as deer enjoy eating the flower buds and leaves.
Plants left in pots unprotected don't usually survive a Calgary winter. If you have plants in nursery containers, but don't know where to plant them, sink them in the ground up to their pot rims in a temporary location. Water them and cover the area with mulch. If you have a cold frame, place the potted plants inside, water them, and then surround and cover the pots with leaves or mulch. Keep the cold frame lid partially open until freeze-up, or moisture may build up in the cold frame and rot the plants.
Perennials grown in containers need to be planted in the ground to survive winter. If you want to use them in containers next year, plant them in the veggie bed and label the spot. In the spring, you can dig them up without being worried about bothering your other plants.
Maintenance and Planning
Cut lawns a little shorter than usual and rake all leaves, to prevent disease. Place the leaves in the green bin. Save some leaves to be added to your compost bin throughout the winter. Apply a winterizing fertilizer.
Improve Soil Quality
Add 5 to 10 cm of compost as a dressing on top of all garden beds to improve the soil. You do not need to work it into the soil as the soil’s creatures will be attracted to its organic content and work it in for you. Compost can be added as a top dressing to lawns. After mowing, rake the compost over the surface, letting the grass blades peak through. If you aerate your lawn, apply compost or a fine textured mulch to fill in the holes. This will improve the soil and prevent frost from damaging the grass roots.
Mulch all perennial borders with compost or a fine textured mulch to minimize temperature fluctuations in the soil, especially during chinooks. Use shredded leaves, dried grass clippings, peat moss, finished compost from the compost bin, straw, or a combination of materials. In most cases, spread mulch in a layer about 10 cm deep and spread up to but not touching plant crowns. You can wait until the ground is frozen before applying the mulch, which will help keep the ground frozen if there are periodic thaws, or you can follow Mother Nature's lead and apply mulch as soon as trees start dropping their leaves. Tender plants of borderline hardiness may be covered with potting mix, peat moss, or fine textured mulch and then covered with leaves for extra protection. You may need to anchor or corral the protection with chicken wire or hardware cloth to prevent it blowing away. This protective cover will need to be removed in early spring. Evergreen perennials, such as dianthus or saxifrage, benefit from a covering of spruce boughs that trap snow and protect against drying winter winds.
Clean Pots and Tools
Fall is also a great time to organize the garden shed. When all the big jobs are done, there are always stakes to be put away and tools to be cleaned and sharpened. Plant containers should be emptied, cleaned, and stored. If you want to get a start on next seasons seeding, fill your seed trays with a plant starting mix, water them, and store them in the garden shed where they can freeze. When you are ready to plant, bring the trays inside the night before to thaw.
Plan for Next Year
While your memories are fresh and phone photos easy to find, write down your thoughts about the successes and challenges you experienced this gardening season. Also make notes about what you would like to do differently, the new techniques you would like to try, and plants you would like to grow.
If you would like to learn more about gardening in the Calgary area, visit our website calhort.org