9 Ways to Refresh Your Garden Soil in Fall for a Head Start on Spring Planting

Plants are only as healthy as the soil they grow in. If you haven’t freshened up your garden in a while, your soil may be more depleted than you realize, or plagued with pests and other problems that will make it harder for plants to thrive.

Autumn is the ideal time to refresh the soil. No matter what type of garden you’re growing, here are 9 ways to ensure your soil is healthy and your garden beds are spring-ready.

1. Remove Diseased Plants

Waiting until spring to cut down dormant or dead plants and remove fallen leaves helps pollinators and other beneficial insects that overwinter in plant debris. However, if you keep an edible garden or your ornamental plants have struggled with pests or diseases during the growing season, it’s best to remove and destroy any plant debris and leaves in the fall. If you wait until spring to clean out your beds, plant pests and diseases may spread to new plantings, causing ongoing problems. 

2. Pull Up Weeds

In addition to diseased plants, you should also pull weeds from your garden as soon as possible to ensure they don’t get the chance to drop seeds and spread. Weeds that haven’t gone to seed are usually compostable. However, it’s wise to keep weeds with mature seed heads out of your compost heap.

Most weed seeds die in compost temperatures above 140°F, and most plant pathogens and pests are killed at 130°F. If your compost pile does not reach these thresholds, seeds, pests, and plant diseases can survive the composting process. Then they could potentially spread to any area where you use that compost.

3. Rake It Flat

After clearing out the weeds and plant debris from your beds, use a rake to smooth the soil and break up any clumps of dirt. This is a good time to fill in any low spots in your garden with compost or a combination of topsoil and compost. Taking the time to level out your soil reduces water pooling and drainage problems and makes it much easier to plant in the spring.

4. Redefine Edges

During the year, planting, weeding, mulching, and mowing all disturb garden edging lines and leave you with poorly defined beds that weeds easily creep into. To remedy this, devote some time in the fall to redefining your garden edges with a garden edger, bricks, edging stones, or a fresh layer of mulch.

5. Do a Soil Test

Plant experts recommend testing garden soil at least once every 3 years to make sure the soil hasn’t become nutrient-deficient or developed a pH imbalance that may interfere with plant growth. If you haven’t tested your soil in a while, do a soil test at home with a home test kit or have your soil tested through your local Cooperative Extension office. Although soil can be tested in spring too, fall is the best time to do it, as it will give you more time before spring to adjust soil imbalances with amendments if needed.

6. Add Compost

Instead of digging up garden soil to remove weeds and break up tough soil, try building your soil from the top down by adding an annual application of compost in fall. Even just 1 to 2 inches of compost spread over your beds helps replenish nutrients, build soil structure, and perk up beneficial soil microbes and earthworm populations that make gardens thrive.

Though you can add compost in the spring, too, applying it in autumn is ideal because it gives the compost more time to become incorporated into the soil. It also reduces the number of gardening tasks you'll need to tackle in spring.

7. Apply Other Amendments

Aside from compost, fall is the perfect time to add other slow-release soil amendments to your garden to fix specific nutrient deficiencies or pH issues that you may have identified with your soil test. Soil acidifiers and alkalizers, in particular, take a while to start working, which is why they’re usually applied before winter. Other products like biochar, gypsum, and livestock manure also break down slowly and are best applied in autumn.

8. Plant Cover Crops

Cover crops are usually planted in vegetable gardens after the harvest and no later than one month before freezing weather sets in to allow them to get established. Often nicknamed “green manure,” cover crops are fast-growing plants that contribute nitrogen and nutrients to the soil when they die back in winter, and they are often used in addition to or instead of standard mulch to reduce weeds. Field peas, crimson clover, and annual ryegrass are just a few popular cover crop options. It’s best to choose cover crop varieties that are not winter-hardy in your area so the plantings don't inadvertently turn into weedy patches in spring.

9. Finish with Mulch

Mulch can be applied either in spring or autumn, but adding a 2- to 4-inch layer of fresh mulch in fall has major benefits. Not only will mulch protect perennial roots from cold damage, but it will also shelter your soil from harsh winter weather, driving rain, heavy snow, nutrient leaching, and erosion. Wood and bark mulch or pine straw are popular picks for ornamental gardens, whereas chopped autumn leaves, weed-free straw, or salt marsh hay are preferred choices for garden beds with edibles.