Ten fall garden tasks to help you prepare for winter

As the growing season winds down, it’s time to think about cleaning up your garden before winter weather arrives. But there’s more to it than stripping away this year’s plants and removing leaves and branches. Here are some autumn tasks that can improve your garden’s health, no leaf blower required.

Fall is the best time to start thinking about spring, says Mary Phillips, head of native plant habitat strategy at the National Wildlife Federation. “Autumn is a really good time for flowering perennials, grasses, shrubs, and trees to get planted so that they take root and come back robustly in the spring,” she says. It’s also the right time to sow native plants, such as milkweed, and ground covers that need cold for seeds to stratify (the process of freezing and thawing that encourages germination).

“In the spring, things like sedges, wild strawberry, and creeping thyme will come up and create kind of a living mulch,” Phillips says. The same goes for grass, says Jennifer Walker, adjunct professor of landscape management and design at St. Joseph’s University in Philadelphia.

“I’ve had the most success overseeding a lawn in the fall,” she says. Spread the seed in the cooler months and it will germinate when conditions are right in the spring.

Fall also is the best time to split established perennials, including peonies and irises, and spread them out, Walker says. She likes to use a sharp spade shovel or a Hori-Hori knife.

“On a peony you can see on the root crown where new growth will happen,” she says. “I just use the tool to gently pry it up, then it’s almost like untangling a cord and it’ll come apart. With irises, you can just expose the roots and break off the tubers and replant them. Next year you’ll have so many irises you’ll have to give them away to friends.”

You may have heard the advice to “leave the leaves,” but there’s even more you can do to help your garden’s inhabitants thrive. “There are whole hosts of beneficial insects and pollinators that overwinter,” Walker says. “Instead of cutting down all the dead stems and stalks, leave them up. Plants like grasses, sunflowers, and elderberries have hollow stalks, and native bees and a few other insects really love those to overwinter in.”

Leaving seeds or fruits on plants means less cleanup for you and provides a source of food for birds and other creatures, Phillips adds. “You can also pile logs, rocks, and branches in a corner of your garden to create shelter for small mammals,” she says. Phillips also suggests setting up a wintertime water source for local fauna: “Pollinators like butterflies and other insects need a very shallow dish with water and some stones in it so they can rest and sip. That’s challenging for the winter, because those ice up really quickly, so putting them in a super sunny location helps.”

In much of the country, late fall and winter bring increased precipitation. Take steps now to reduce flooding and runoff that could hurt dormant plants and leave you with less topsoil in the spring.

“When plants aren’t actually growing and pulling up moisture, we see a lot more saturated soils and flooding,” Walker says. Mitigate the problem, she says, by “cleaning drains, swales, and gutters, and making sure that water can move through during winter storms.”

Unhook hoses and drain them completely so they won’t be damaged by freezing temperatures. “Make sure there’s no water in the hose, then attach one end to the other to keep any from getting in,” Walker says. “Also, shut off the water to your hose taps from inside if they’re not winterized. Water hanging in the end of the faucet will freeze and crack it.”

Clean your garden tools before storing them for the winter. “I use a wire brush to remove loose dirt, give them a bit of a wash, sandpaper off any rust and coat with something like linseed oil,” Walker says. Sharpen your snips, shears, loppers, and pruners (or take them to a local sharpener), and don’t forget your shovels and spades.

“A lot of people don’t understand shovels are meant to be sharp,” Walker says.

Some preparation in the fall can help protect plants, even if winter temperatures drop well below freezing. Wrap containers and pots in burlap, old blankets or bubble wrap to keep the root systems inside warm.

A layer of mulch protects the soil (and the plants below) by helping to prevent a deep freeze. Some types of mulch generate more heat than others. For example, the air pockets in wood chip mulch retain more heat than leaf litter or straw. In an area where the soil needs a boost, a layer of wood chips can keep the worms underneath extra warm and allow them to work through the winter, Walker says. But mulch carefully: In other parts of the garden, too much heat can be a bad thing. Piling wood chips around the base of trees, for instance, can encourage fungus and make the trunk and shallow roots too hot.

“If you have a lawn that you want to make into a garden bed in the springtime, fall is a great time to do sheet mulching,” Walker says. Sometimes called “lasagna gardening,” sheet mulching involves covering an area to kill the grass or weeds, then adding layers of organic material that will break down into a rich growing medium. “The simplest way is just to lay down cardboard, then a couple inches of compost, a couple inches of a heavier mulch like a wood chip, and just let that exist over winter,” Walker says. “The macroinvertebrates are going to be turning that soil and doing a lot under there.”

Garlic and onions deter pests, so sowing them near other plants can prevent critters from digging up roots and bulbs. They also provide an early edible crop, and even if you’re not a veggie gardener, their blooms can be a pretty addition to flower beds or other landscaped areas.

The best part: They’re incredibly easy to grow in many places. Just plant the bulbs in the late fall, add a layer of mulch and reap the benefits come springtime.

Just because there’s little work to do in the garden over the winter doesn’t mean you should stay away. It’s a great time, Walker says, to get to know your surroundings on a deeper level.

“The main thing that I suggest is to really get curious and excited about what happens in the fall and winter,” she says. “Find out what might be growing and where the insects are hanging out. Break out a magnifying glass and just see what you can find.”

There’s a lot going on out there, Phillips adds.

“Your space is truly a habitat, and that is a year-round thing,” she says. “People really focus on the summer and the blooming plants, but there’s still a lot of life happening under the soil and under the snow. The more you can do in the fall to make that a lush environment, it’ll help all those wonderful species thrive all year long.”