Overwintering Plants & Other Important Fall Gardening Tasks
Overwintering Plants & Other Important Fall Gardening Tasks
September 21, 2018
After a bountiful season, it’s time to prepare your garden for winter—and ensure a beautiful and vibrant spring! Here’s everything you should do to get your garden ready—from cleaning out the vegetable garden to protecting trees and shrubs.
Preparing Your Vegetable Garden for Winter
You can postpone the inevitable (that is, winter) for a while by covering your vegetables with old sheets or bedspreads on cold nights, but the declining light and chilly daytime temperatures will naturally bring plant growth to a halt. Get tips for protecting your garden from frost.
- Root crops (like carrots, turnips, beets, rutabagas, and parsnips) can remain in the garden after a frost and still be removed in good condition later, but get them dug and stored before the ground freezes. Some crops—parsnips especially—taste better when they are allowed to mature at near-freezing temperatures for 2 to 4 weeks.
- Potatoes can also stay in the soil, but it is important they be dug and removed from the garden almost immediately and not left on the soil surface for any period of time. So dig and remove the potatoes to a dry, warm area out of the sun to begin the process of letting the skin toughen up for storage. Dry in a single layer and turn periodically. This takes about two weeks. Carefully remove visible dirt from the potatoes, but do not wash them: their skins will toughen for longer winter storage.
- Leafy greens like kale and collards actually become a bit sweeter with a light frost. Cabbages and Swiss chard can withstand light frosts, but outside leaves may get damaged or tough (just peel them away before using the rest of the greens). Lettuces, however, cannot handle the frosts.
- Other plants, like tomatoes, zucchini, peas, beans, and pumpkins, should be pulled up and disposed of. If the plants are disease-free, compost them. If any are diseased, either burn them or discard them in the trash. Pull up, clean, and put away any stakes or supports.
- See our Growing Guides for more plant-specific advice.
Cleaning Up The Garden
- Before the ground gets too hard, remove all weeds and debris and eliminate overwintering sites for insects and disease. Check our Plant Pests and Diseases Library for tips on preventing and preparing for the most common pests in your garden.
- Gently till the soil to expose any insects who plan to overwinter; this will reduce pest troubles in the spring and summer. This is one of the most effective ways to reduce populations of Japanese beetles, whose grubs live and overwinter in the ground.
- Once most of the garden soil is exposed, add a layer of compost, leaves, aged manure (if you have it), and lime (if you need it). Gently till into the soil.
- Another option is to sow cover crops, such as winter rye, to improve your soil. See our articles on Cover Crops for the U.S. and Cover Crops for Canada.
- If some parts of the garden have hopelessly gone to weeds, cover them with black plastic or a layer of cardboard and leave it in place through the winter season. This will kill existing weeds and subdue sprouting seeds.
Preparing Herbs for Winter
Herbs are a mixed bag when it comes to needing winter protection. Some are very hardy and can easily tolerate a cold season, while others will need some extra help:
- Sage is a perennial in most areas and does not need special treatment for the winter. Before frost stops its growth, cut a branch or two to dry and use in stuffing at Thanksgiving! (Try our delicious stuffed turkey recipe with sage.)
- Rosemary is a tender evergreen perennial that should be sheltered outside (Zone 6) or potted up and brought inside (Zone 5 and colder) for the winter.
- Thyme is fairly indestructible. A perennial, it will go dormant in the fall, then revive by itself in the spring.
- Parsley, a biennial, will withstand a light frost. In Zone 5 or colder, cover it on cold nights. It has a long taproot and does not transplant well.
- Chives are hardy perennials. Dig up a clump and pot it, then let the foliage die down and freeze for several weeks. Bring the pot indoors to a sunny, cool spot. Water well and harvest chives throughout the winter.
- Basil is a tender annual that won’t survive outside in most regions of North America. Dig up small plants and bring them inside to extend their season.
- Oregano is a perennial that is somewhat hardy, but will appreciate some winter protection in the form of a layer of straw mulch.
Preparing Berry Patches for Winter
Berries tend to be hardy, but do require some fall pruning and care:
- In early to mid-fall, prune summer-bearing raspberries, leaving six of the strongest brown canes for every 1 foot of your patch.
- Prune fall-bearing raspberries ruthlessly, cutting them to the ground after they have borne fruit. New canes will come up in the spring and bear fruit.
- Plant blackberries in the fall and mound up the soil around the canes to prevent hard frosts from heaving them out of the ground.
- Many blueberry varieties are hardy, but they will appreciate a thin layer of mulch around their base for added protection.
- Cover strawberry beds with a layer of straw mulch.
Preparing Perennials and Flowers for Winter
- Water your perennials and flowering shrubs in the fall; they will thank you for it this winter.
- Once the ground has frozen hard, cut perennials back to 3 inches and mulch them with a thick layer of leaves or straw.
- If you plan to put in a new flower bed next spring, cover that area now with mulch or heavy plastic to discourage emergent weed growth when the ground warms up in the spring.
- Before a heavy snowfall, cover pachysandra with a mulch of pine needles several inches deep.
- Move potted chrysanthemums to a sheltered spot when their flowers fade. Water well and cover with a thick layer of straw to overwinter them.
- When a frost blackens the leaves of dahlias, gladioli, and cannas, carefully dig them up and let them dry indoors on newspaper for a few days. Then pack them in styrofoam peanuts, dry peat moss, or shredded newspaper and store in a dark, humid spot at 40° to 50°F (5 to 10°C) until spring.
How to Overwinter Geraniums
- Geraniums (Pelargoniums) are South African in origin, and there they have a three-month dormant period during winter’s excessive dryness. They need to be kept well watered before going into dormancy.
- In the old days, we had cool cellars with dirt floors that were dark and moist. Our mothers shook the dirt off geranium roots and hung them upside down in bundles. In spring, they were cut back and potted up, and performed nicely.
- If you have a cool place in your house (around 50°F/10°C), it is possible to overwinter your geraniums by keeping them in their pots and giving them very little water.
- In spring, bring them into a warm place and water them heavily. When they start to show buds, repot them and prune heavily.
- They will do best in plastic or glazed pots with very good drainage. (You can overwinter geraniums as houseplants without letting them go dormant, but they will be deprived of the rest they like.)
- You may water roses regularly through the fall; refrain from fertilizing starting 6 weeks before the first fall frost.
- Remove any dead or diseased canes.
- After the first frost, mulch plants with compost or leaves to just above the swollen point where the stem joins the rootstock.
- In areas where winter temperatures are severe, enclose low-growing roses with a sturdy cylinder of chicken wire or mesh and fill enclosure with chopped leaves, compost, mulch, dry wood chips, or pine needles.
- Before daily temperatures drop well below freezing, carefully pull down the long canes of climbing and tea roses, lay them flat on the ground, and cover them with pine branches or mulch.
Preparing Trees and Shrubs for Winter
- Protect small trees or shrubs from extreme cold by surrounding them with a cylinder of snow fencing and packing straw or shredded leaves inside the cylinder.
- Fall is a good time to plant trees and shrubs. Here’s a list of some of our favorite shrubs to plant at this time of year.
- Inspect your trees. Remove any broken limbs, making a clean cut close to the trunk.
- If you’re planning to buy a live Christmas tree this season, dig the hole where you’ll plant it before the ground freezes. Store the soil you remove in the garage or basement, where it won’t freeze. Place a board over the hole and mark the location so that you can find it if it snows.
Garden Chores to Do Before Winter
- Empty all of your outdoor containers to keep them from cracking during the winter. Store them upside down.
- Hang a bucket over a hook in your toolshed or garage and use it to store hose nozzles and sprinkler attachments.
- On a mild day, run your garden hose up over a railing or over the shed to remove all the water. Then roll it up and put it away.
- Mow your lawn as late into the fall as the grass grows. Grass left too long when deep snow arrives can develop brown patches in the spring.
- Don’t leave fallen leaves on the lawn. Rake onto a large sheet or tarp, then drag to your compost pile in thin layers mixed with old hay and other material. Or, rake the leaves into loose piles and run the mower over them to turn them into mulch for perennial and bulb beds. Get more tips on what to do with fall leaves.
- Cover your compost pile with plastic or a thick layer of straw before snow falls.
- Drain the fuel tank on your lawn mower or any other power equipment. Consult the owner’s manual for other winter maintenance.
- Scrub down and put away your tools. Some folks oil their tools with vegetable oil to avoid rust. Find out how to care for your gardening tools.
- Check out our list of fall garden chores to make sure you have everything done before the winter hits!
We hope these tips will help your garden survive winter and thrive in spring! Please share your own advice or ask any questions below!