3 Soil Amendments To Try This Fall

What should I add to my garden soil in the fall?

Healthy garden soil

Boost your garden soil in the fall — next season's seedlings will thank you.

When the garden season winds down, it's time to think less about fruits and flowers — and more about garden soil. After all, there is no garden wealth without soil health!

3 Amendments to Add to Your Garden This Fall

Below are 3 different amendments (in order of increasing complexity) to add to your garden soil this fall. Try 1, or experiment with all 3!


Autumn is a good time to improve your soil by adding raw organic matter, such as shredded leaves.

1. Leaves

Leaves are cost-effective (ok, FREE) and provide tons of benefits for the garden. When we bag up our leaves and truck them off to a landfill, we are essentially getting rid of precious nutrients and organic matter. Instead, add leaves to your compost bin as a carbon-rich "brown" or get shredding with a leaf shredder. Shredded leaves adds nitrogen to the soil, helps feed worms and other beneficial decomposers, and adds organic bulk to sandy, nutrient-poor soils. Leaves from fruit trees, beech, maple, and birch trees are great leaves to use. Growing an acid-loving plant like blueberries or azaleas? Try mulching with pine needles, oak leaves, or other high-nitrogen tree.

2. Compost

Whether you are using your own homemade compost, or are purchasing compost in bags or by the truckload, your garden will thank you for the boost that compost brings. Whether your soil is currently hard and compacted, sandy, stony, heavy, or wet, adding compost will improve its texture, water-holding capacity, and fertility. Your soil will gradually become fluffy and brown—the ideal home for healthy plants.

Compost is teeming with all kinds of microorganisms and soil fauna that help convert soil nutrients into a form that can be readily absorbed by your plants. The microorganisms, enzymes, minerals, and natural antibiotics that are present in compost actually help prevent many soil pathogens from harming your plants. Earthworms, millipedes, and other macro-organisms tunnel through your soil, opening up passageways for air and water to reach your plants' roots.

Shoveling out finished compost

Make heaps of nutrient-rich compost in your own backyard with the Demeter 3-Bin Composter.

Use compost anywhere your soil could use some love:

In the vegetable garden. Amend soil each spring with a layer of compost. You can gently mix it into the top few inches of soil, or mulch around individual plants or rows. In fall, as you remove spent crops, loosen soil and mix in a 3" to 4" deep layer of compost. Then cover bare soil with shredded leaves or straw. The soil will be refreshed for spring planting.

Pamper perennials. As you tidy up perennial gardens — in spring, fall, or anytime in between — keep a bucket of compost at hand so you can spread a 1" layer around the base of each plant, keeping the compost a few inches from the stems to prevent rot.

Nurture shrubs and trees. Don't take 'em for granted — they're your biggest landscape investment! In spring and fall, spread a 3" layer of compost in a wide band extending well beyond the edge of the canopy. Keep the compost 6" inches away from stems and trunks to prevent rot.

Give bulbs a boost. Mix in a few handfuls of compost into each bulb planting hole, or prepare an entire bed by mixing in a generous layer of compost before planting.

Lawns are plants, too! Apply a 1/2" layer of compost over your entire lawn each spring and fall. If soil is compacted, rent an aerator first to open up the soil so water will wash the compost down to the grass roots.

3. Cover Crops

Widely used by farmers, cover cropping is just beginning to creep up in popularity with gardeners. Use cover crops to feed the soil, build humus, smother weeds, and prevent erosion. These plants not only help replenish tired soil—they can also increase the number and variety of beneficial insects and other organisms in the garden. Although many plants can fulfill more than one function, it helps to categorize cover crops according to their main contribution:

  • Legumes, like alfalfa, clover, beans, and peas, have nodules on their roots that can convert nitrogen in the air to a more useable form it in the soil. They improve soil fertility.
  • Deep-rooted plants retrieve minerals from deep below the surface, making them available to other crops. These include buckwheat and alfalfa.
  • Some plants, such as mustards, rapeseed and ryegrass, produce compounds that inhibit the growth pest organisms and weed seeds.
  • Grassy and densely rooted cover crops, such as buckwheat and rye, prevent soil erosion and moisture loss by covering the soil. They also inhibit weed growth by shading the soil and competing for moisture.

To prevent the cover crops from becoming weeds themselves, it’s important to cut them down and turn them under before they go to seed. After they’ve been added to the soil, they decompose and release their nutrients.

Clover, ryegrass, and other cover crops deter weeds, conserve moisture, and add nutrients to the soil when tilled under.

Clover cover crop


Last updated: 10/02/2023