What a gift to be a gardener at this time of year! For most other people, winter just grinds on, with dingy snowdrifts melting into puddles that will freeze into ice slicks. But gardeners don’t have to just mope indoors, dreaming of summer. They can get to work.
“There’s plenty to do in the middle of winter to get ready for spring,” said Sharon Yiesla, plant knowledge specialist in the Plant Clinic at The Morton Arboretum in Lisle. “It’s a great opportunity to think ahead for a more successful and satisfying garden this year.”
Here are some winter tasks to get your gardening season started and keep cabin fever away.
Make a plan. Review any notes you took about last year’s garden, or look through pictures on your phone to help you recall. Think about what you’d like to improve this year, such as more color, more privacy, more winter interest or more wildlife habitat. Measure your yard with a long tape measure and sketch a rough plan. “Get a clear sense of the space you have to work with before you start thinking about choosing plants,” Yiesla said. Be especially careful to look up, so you don’t make a plan to plant trees or large shrubs where they will grow to collide with power lines.
Research plants carefully. “It’s easy to fall for a gorgeous picture of a new plant in a catalog or a website, but give it some thought before you set your heart on it,” she said. Consider whether the plant will really work for the space and conditions in your garden. It’s especially important to make careful choices of trees and shrubs, which are long-term commitments. The search tool on the Arboretum’s website (mortonarb.org/search-trees-and-plants) can help you learn about the many kinds of plants and make better choices.
Prune deciduous shrubs. Get outside and use sharp hand pruners to shape up any shrubs that need it. Learn the right approach and timing for pruning many kinds of shrubs at mortonarb.org/pruning-deciduous-shrubs. Look around for any branches that have been broken by the weight of heavy snow or ice and prune the stubs cleanly back to a main stem or near the ground.
Order seeds. Browse catalogs and websites for interesting varieties. “Just be realistic about how many vegetables or flowers you have space for,” Yiesla said. It’s a good idea to make a rough planting plan of your in-ground garden or raised beds to be sure you don’t over-order.
Schedule your seed-starting. Use the seed packet or catalog description as a guide to figure out how many weeks before the last frost date you should start seeds indoors under lights. “We generally expect the last frost in mid-May, although spring weather can be volatile and there are no guarantees,” she said. It’s smart to start seeds in two or three batches a week apart to increase the odds that you will have seedlings ready to transplant outdoors when the chancy weather allows.
Cut back grasses. Remove the old, dry stems from ornamental grasses before March, when new growth will likely begin. “Cut them down within a few inches of the ground, but don’t cut into the base of the plant,” Yiesla said.
Plan and build raised beds. Choose a spot for vegetable beds that will be in full sun for at least six hours a day. Allow space around each bed for a wheelbarrow to pass. Make beds no more than 4 feet across so you can reach in to weed and harvest. “There are plenty of plans online for build-it-yourself raised beds, or you can buy kits,” she said. Beds that are 8 inches deep can accommodate shallow-rooted crops such as spinach, lettuce and radishes. Tomatoes, peppers, carrots and other plants with deep roots need at least 12 inches of soil depth.
Check perennials for frost heaving. The freeze-and-thaw cycle so common to Chicago winters, when warm spells and cold spells follow each other, is hard on perennials. The soil around their roots may freeze and be heaved up as the ice expands, only to leave the roots stranded aboveground when the ice melts. “Shallow-rooted plants, such as those that were just planted in fall, are most vulnerable, especially if the soil isn’t insulated with a layer of mulch,” Yiesla said. Look around for displaced perennials on a warm day and gently push each root mass back into the soil. Then spread some mulch to protect plants against future weather swings.
Clean, sharpen and sterilize garden tools. Wash tools in water to remove dirt, dry them and use steel wool to remove any rust. Then sharpen pruners and loppers with a small diamond file or pruner sharpening stick, available at hardware stores. For shovels and hoes, use a medium-cut 10-inch file. After sharpening, wipe pruners and loppers with 70% rubbing alcohol to sterilize them. Use a light household oil to lubricate the action of cutting tools. Wipe the business ends of all your tools with the same oil to deter rust.
For tree and plant advice, see the online resources of The Morton Arboretum at mortonarb.org/plant-care, or submit your questions online at mortonarb.org/plant-clinic or by email to plantclinic@mortonarb.org. Beth Botts is a staff writer at the Arboretum.
