Preparing raised beds for winter, if you garden in them, should be an essential part of your autumn to-do list. I have several raised beds, and there are a few steps I take before I call it a season and give my green thumbs a break for the winter. Some of those tasks I start to think about in late summer. Others I try to make sure I do as I don more layers to go outside and finish up before the snow flies.
Why is preparing raised beds for winter important?
What I appreciate about the changing of the seasons in the fall is it gives me the opportunity to really give things a once over. When I’m no longer watering, looking for signs of pests, staking and pruning plants, etc., I have time to assess. The end of the official growing season—even if you’re still growing winter crops—is a great opportunity to feed your soil, get a head start on next year, and take stock of winter project planning for spring fixes and builds.
So as I take apart my containers, put my watering cans and décor items away, and drain my hose, I’m also milling about my raised beds pulling weeds and spent plants, applying winter mulch, and safely storing plant supports, among other tasks. And the fall leaves that blanket my backyard? They come in handy, too, as mulch and as stellar soil amendments. Here’s what you need to add to your list.
Pull out all spent vegetable plants
Even though we advocate for not cleaning up your fall garden so as to feed and shelter beneficial insects, birds, and other wildlife, that reasoning applies more to not cutting back a lot of your annuals and perennials.
Anything that is annual in your veggie garden, on the other hand, pull it out—especially fruiting plants, like tomatoes, ground cherries, and tomatillos. I mention these ones in particular because if you let the fruits fall in the garden and just leave them be for the winter (I’ve missed some in the past when I’ve done a cleanup), you’ll be pulling them out as weeds in the spring.
Furthermore, rotting vegetables can attract pests. Insect pests and diseases can also overwinter in the soil, so you want to at least make an effort to prevent them from returning by pulling out all dead vegetation.
Protect perennial plants
The exception is perennial herbs, like sage, chives, thyme, and oregano. If you give them some protection, you can harvest them all winter. Otherwise, I leave them be and they come back in the spring. I have one raised bed that is full of oregano, chives, and sage. I harvest when there is no snow cover, but once it snows, I wait until spring to enjoy them once again.
I also overwinter hardy greens, like kale in my raised beds. You may want to cover it with frost protection, depending on where you live. In the past I have overwintered a single kale plant over three winters!
Perennial vegetables can be mulched for winter harvests, like Jerusalem artichokes, or to protect them from the elements (like asparagus crowns).
Get a head start on weeding for next year
Before I plant garlic, usually in October, I’ll give the raised garden bed soil a close inspection, pulling out clover, purslane, and chickweed, and any other weeds I see lurking about. I’ll then move on to the other raised beds that may sit plant-less for the winter (though not uncovered, more on that below). All the weeds are removed, so nothing can germinate over the winter.
Plant cover crops as a part of preparing raised beds for winter
Cover crops can help keep those weeds away, while also adding organic matter to the soil. Examples of cover crops include winter rye, buckwheat, legumes, like clover, as well as pea and oat mixes. However you need to think about planting cover crops well before autumn. Fall cover crop seeds are generally planted at least a month before your region’s hard frost date. Check the seed packet carefully, though, as some seeds need warmer temperatures to germinate, while others don’t mind cooler temps. Here are some tips on growing cover crops.
Remove stakes and plant supports
I also sometimes find plastic plant tags that I’ve used to mark certain crops and varieties of things I’ve planted. Those get dusted off and put away so I can reuse them when I start my seeds in the new year. Anything not reusable is thrown out so it doesn’t inadvertently make it into the compost. Worth noting is the fact that plastic is a big issue in compost that’s processed in facilities that take yard waste bags.
Preparing raised beds for winter with season extenders
If you are extending your growing season with hoop tunnels, for example, make sure your hoops and brackets are ready for frost warnings, so you can set up quickly, and your floating row cover is folded up somewhere where it’s easy to grab.
If you’ve packed up the vegetable garden, you may also want to have these items handy in a shed or garage for early spring planting. One of the benefits of gardening in raised beds is the soil warms up sooner in the spring. Have plant protectors handy for when you plant cool-weather spring veggies, such as peas, kale, root crops like beets, etc.
Check for shifting boards and other fixes you’ll want to tackle in spring
One thing I wish I had added to some of my raised beds is a mid-point stake along each long side. For my 4×8 raised bed that has mid-point stakes at the middle of each eight-foot length, this has meant that the top and bottom layers of wood have not shifted with freeze-thaw cycles over the last few years, like they have in other beds.
Make note of shifting or rotting boards that may need to fixed or replaced in the spring—or that can be fixed immediately, so they’re ready for next year’s growing season.
Winter is also a great opportunity to dream of new raised bed projects. Here is some inspiration if you’re looking to add to your collection.
Amend the soil in raised beds
One question I often get from new gardeners is whether you empty your raised beds for the winter. The answer is you leave the soil, but you’ll continue to amend it over time to replace the nutrients that have been used up by the plants and leached out by watering.
Soil can be amended in the fall, in the spring, or both. I like to amend in the fall, when I’m preparing raised beds for winter, so that they are prepped and ready for early-spring crops.
Once my raised beds have been emptied of annual flowers and veggies, I add a few inches of compost. This may be aged manure or a bag of vegetable compost. I also add mulch (mentioned below).
Add winter mulch when preparing raised beds for winter
If I don’t get around to adding compost, I still take the opportunity to feed the soil by adding chopped fall leaves as a winter mulch. I live on a ravine, so I have a LOT of fall foliage. Some leaves are sent to the compost pile. And then I’ll chop some leaves up to add to my raised beds (and other garden beds). They will break down and nourish the soil over the winter. Covering the soil in your raised beds also helps to prevent erosion.
The first thing I do after planting my garlic is cover it in straw. Not only does this act as a winter mulch, it also hides the freshly dug soil from the squirrels. Even though they dislike garlic, they’re still curious about what’s happened in the garden. Other crops that can be grown in winter, like carrots, can be deeply mulched for later harvests.
Check for slugs
This tip is especially useful if you’re continuing to grow in covered raised beds through the autumn months. Be on the lookout for slugs. They are prevalent in the fall, especially after a mild, wet season. Check the nooks and crannies of your raised beds to see if they’re hanging out, lying in wait until they’re hungry for your crops. Here’s a helpful article on how to get rid of slugs organically.
More fall gardening tasks and info
- Grow garlic in pots
- Decide which garlic varieties to plant
- Learn how to garden with a cold frame
- Dig in fall flower bulbs
- Overwinter cucamelon tubers
- Trim off rose of Sharon seed pods