Should I Cover My Garden in the Winter?

Should I Cover My Garden in the Winter?

In Lawn & Garden, Winter by Jamie

As the days of harvest end and frost-filled nights kill the remaining vegetation, it’s tempting to just sit back on a well-earned winter break, but there’s one more task to tackle. Since spring is such a busy gardening season already between sowing seeds, preparing beds, and transplanting plants, you’ll save yourself from early spring weeding and composting by covering your garden for the winter.

Covering your garden in the winter will suppress early spring weeds, help protect the beneficial microbes and insects living inside the garden from frost, while also preventing erosion from wind and snowmelt. By applying compost now (either as the cover or underneath another cover), the nutrients will break down over the winter and provide a healthy boost come spring.

Should I cover bare soil in the winter?

Yes, you should cover bare soil in the winter. A light covering will help protect the beneficial microbes and insects overwintering in the soil from freezing temperatures, while allowing the topmost layer to freeze, killing off some overwintering pests and overwintering diseases. It also helps prevent erosion from wind and from snow melt.

Mulch will also help you win that battle against fall weeds and early germinating weeds. Bare soil is the first stage of desertification, and nature has developed its ways to prevent that, namely through plants that can quickly land and grow wherever there’s bare soil. (They don’t know that you were actually going to plant something else there, honest!) Mulch will help prevent weed seeds from germinating in early spring and help smother out the weeds that just got away from you in the fall.

Should I cover my vegetable garden in the winter?

Yes, you should cover up your vegetable garden during the winter, just as you’d want to protect bare soil. Covering a vegetable garden during the winter will help prevent erosion and suppress weeds. If you use an organic mulch like compost or cover crops, they’ll even improve the quality of your soil over winter.

When should I cover my garden?

When preparing your garden beds for the winter, cover them with a mulch after you remove the remaining plant matter (vegetable beds) and before the first snow. If you’re trying to protect your existing garden plants from a late or early frost, cover plants in the evening when the wind dies down and uncover the next morning as temperatures climb. (Mulch will also help protect plants from frost!)

What should I use to cover my garden?

You’ve got a few options to use for covering your garden:

  • While we often think of compost as a spring task, the best time to apply compost is in the fall. A layer of compost will start breaking down into nutrients in the fall, continue breaking down until the ground freezes, then pick back up as soon as the ground thaws, giving your plants a nutrient boost come planting. For best use, cover the compost with a light layer of another mulch to curtail nutrient erosion (so nutrients stay in your garden bed).
  • Bark mulch and sawdust. If you normally mulch your flower beds with bark mulch, keep it in place or give it a refresh.
  • Straw and hay. If you have a good source for organic straw or hay that hasn’t been sprayed with persistent herbicides, use it! If you’re not sure about the herbicide history, don’t use it (you could end up killing your plants). Straw is usually better than hay, as hay can contain seeds.
  • Dried leaves. Gardeners are often too fastidious when it comes to cleaning up all those leaves. While they can’t remain on grass, any plants that originate from the woodlands will love a nice layer of dead leaves for protection and spring nutrients. By the time spring comes, they’ll be half-rotten and good for either leaving in place or the compost heap.
  • Cover crops. Cover crops are quick-growing plants sown in late August or in the fall, that grow quickly and protect the soil during the winter while improving the soil and preventing weeds. They will be winterkill (the frost kills the crop) or non-winterkill (you’ll need to kill it with a crimping device in the spring). Growing cover crops has a learning curve, but once you get the hang of it, it’ll become routine.
  • Tarps, landscape fabric, and cardboard. If weeds have overtaken your annual garden beds, covering them with tarps, landscape fabric, or cardboard will kill most weeds by spring. Cardboard will compost, while tarps and landscape fabric can (and should) be reused. The dead weeds will break down into compost.
  • Hoop houses, row covers, and cold frames. If you’re trying to keep your cold-hardy vegetables going past the last frost date, then a hoop house, row cover, or cold frame will increase the heat a few degrees.

How do I winterize raised garden beds?

To winterize your raised garden beds (or any garden beds):

  1. Clean up the garden beds. Pull any remaining weeds and remove any remaining plant detritus, especially if during the growing season you had any pests and/or diseases that can overwinter. If weeds have taken over your entire garden bed (don’t worry, we’ve all been there), cover the raised bed with a tarp, landscape fabric, or cardboard to smother out the weeds. If you don’t have enough time before snowfall to kill the weeds and prepare the beds, just do this.
  2. Grab a soil sample. If you’re planning on doing a soil sample to check on the general health and available nutrients in the soil, now’s a great time. Just remember that the next step, adding compost and amendments, can affect this.
  3. Fill in the holes. After removing weeds and roots from the raised bed, you’re probably left with a bunch of holes. Even out the existing soil to fill in the holes.
  4. Apply compost. Apply a layer of compost between two and four inches. The compost will break down over the winter and early spring, so your raised bed will be ready for spring. This will also help bring the soil level back up. This is also a great time to add any other amendments.
  5. Apply mulch. A thin layer of natural mulch will suppress weeds and prevent erosion while the ground freezes, killing off residual pests and disease. The downside is that the microbiology will also die, although it can also move deeper into the soil. If you’re using cover crops instead, sow the cover crop.
  6. Check the raised bed structure for any needed repairs. If the boards are rotting or coming loose, replace them or nail them back in so that the beds are ready come spring. You can also wait until spring if winters are especially harsh on wood.
  7. Review your growing season and make notes for next year. As much as we gardeners like to believe that our memory is infallible, it’s a good idea to take the time to write about what went well, what didn’t go well, and what changes you’d like to make next year. That way, when the seed catalogues arrive, you know (almost) exactly what you want to do.

And remember to enjoy fall and take a well-earned rest in winter, as you’re now prepared for spring.

Final thoughts

Taking the time to cover your garden with compost and other mulches in the fall or early winter means you’ll have much healthier soil and much less hassle in the early spring. Before applying mulch, remove the remaining vegetation (especially perennial weeds) to prevent pests and disease from overwintering. You’ll thank yourself next year.

What about your lawn? Check out our winter lawn care guide for Canadians