Just because the growing season is over doesn’t mean the work with your raised garden bed is over, too. From covering the raised garden bed with leaves to sowing a winter cover crop, you have several options to draw from to keep the soil healthy and reduce a winter weed invasion. Here are six things you can do to winterize your raised garden bed.
1. Remove plants from the raised bed garden
After a killing frost or freeze, clean up any remaining or dead plants from the raised garden bed. Put the debris in the compost pile or discard in the trash. Remove, clean, and store tomato cages and other plant supports from the vegetable garden. Finally, smooth out the bed’s soil.
2. Increase soil in the raised bed
The soil naturally settles over the growing season. Add layers of compost, planter’s mix or other organic matter to raise the soil level to a few inches below the raised garden bed’s frame.
3. Cover the soil in the raised bed
Bare soil in cold weather is an open invitation to weeds and other undesirable plants. You have lots of ways to cover the soil.
- Probably the easiest are the leaves Mother Nature gives you in fall. A two or three inch layer of shredded leaves is perfect for this job, especially for the DIY person. Pick up the leaves in a catcher attached to a mulching mower and dump the shredded leaves on the raised garden bed. The shredded leaves will decompose during the winter season, nourishing microbes in the soil, adding nutrients, and improving its drainage and quality. Come springtime, work the chopped leaves into the top few inches of soil.
- Leaves that have not been shredded can also be used as a mulch, but they may have to be removed in spring, especially if still intact. If leaves have started to decompose in spring, work them into the top few inches of soil.
- Plant a winter cover crop. Also called green manure or living mulch, sow seeds of winter rye, clover, peas, and other legume family members. Heavily sow the seeds and water every day for three to five days. These crops grow through winter and help prevent soil erosion and compaction from rain.
- Chop down or weed whack the cover crop plants in early spring, leave them to dry, then dig them into the top few inches of the soil. Make sure you chop down any plants before they bloom. If allowed to flower, set seed, and disburse it, the plant could become a weed in the summer garden.
- Cover the soil with about 2 inches of finely shredded bark or pine fines (aka finely shredded pine bark). These decompose reasonably quickly to add nutrients to the soil and improve its structure.
- If none of these options works for you, cover the raised garden bed with landscape fabric. This material allows for light and rain penetration, but it keeps the weeds out. Remove in spring.
4. Test the garden’s soil
Fall is the perfect time to test the soil in the raised garden bed. The test divulges the nutrients and minerals in the soil and makes recommendations on how to improve it. You can make the improvements with amendments in fall or spring.
At-home soil tests are available, but their results aren’t always detailed. For the most detailed results, contact your local cooperative extension for instructions on how to prepare a soil sample for laboratory testing.
5. Inspect the raised garden bed’s frame
Make sure the soil under the frame has not eroded. If it has, you’ll need to shore that up, adding more soil where needed. Make sure the corners of the raised garden bed are still square and solid. Replace rotted wood to help prevent collapse of the frame and pest invasions.
6. Consider extending the raised bed garden’s season
Winter is an excellent time to think about extending your garden’s season. Look at row covers if you’d like to plant earlier next spring and keep crops growing well into fall and winter. Tent the cover above the bed. The cover helps insulate overwintering plants, keeping them about 10 to 15 degrees Fahrenheit warmer than the ambient temperature.
Installation Tip: Pound 8-inch-long PVC pipes into the outer edges of the bed. Pound them until 1 inch is above the soil level. Use a slightly smaller diameter piece of PVC pipe to bend or arch over the bed. The height of the arched PVC pipe can be 12 inches or higher. Place and secure the row cover over the arch.
FAQ about winterizing raised garden beds
It’s OK to leave perennials in the bed. If you have garlic planted, you can leave that, too. Just work the mulch around the plants in the bed.
Many vegetables, including spinach and carrots, can stay in the garden well into winter. Cover these plants with a foot or two of straw. Move the straw to harvest the plants, then put it back.
When to call a gardening pro
If winterizing or tending your raised garden bed seems overwhelming, consider contacting a professional gardener. A professional can handle many of your gardening needs, from making new beds to planting trees and shrubs.