How to Build Healthy Soil Now for Spring

Published Sep 27, 2026 6:31 am : Updated Sep 27, 2026 6:35 am

Photo taken by: Tracey Petersen

Healthy soil is the foundation of a thriving garden. It supports plant growth, provides nutrients, and creates an environment where beneficial organisms can flourish. But by the end of summer and into early fall, many gardeners are feeling a little exhausted. Some may even hesitate to visit their gardens, faced with overgrown plants, weeds, and the thought of pulling out old crops and preparing for a new season.

But fall is one of the best times to start preparing your garden for spring. Rather than turning over the soil, digging out every root, or starting from scratch, you can use the no-till gardening method to build healthier soil while making spring preparation easier.

Whether you are creating a new garden bed or refreshing an existing one, no-till gardening offers a simple way to improve the soil while minimizing disturbance. You can use this method in many locations and soil types. One approach is called sheet mulching, which uses layers of cardboard and compost to help establish a new growing area.

Begin by cutting down existing grasses, weeds, and other vegetation close to the ground. Cover the area with plain, uncoated cardboard, overlapping the edges by several inches to minimize gaps where weeds could grow through. Remove plastic tape, labels, and staples. Wet the cardboard thoroughly so that it begins to soften. Then weigh it down with rocks or use garden staples.

Cardboard can help suppress existing vegetation by blocking light while it gradually breaks down. You can often add 4-6 inches of compost immediately after laying and wetting the cardboard or you can choose to wait a few weeks and then add the compost. Compost adds organic matter and nutrients and provides a favorable environment for soil organisms. The cardboard will decompose overtime beneath the compost and will act as an excellent weed barrier in the first year.

The key is to disturb the soil as little as possible, keep it covered in between seasons (with a tarp or mulch) and keep it growing with plants, food crops or flowers as much as possible. In subsequent years, you will need to add about 2 inches of fresh compost and a mulch of your choice around growing plants, such as seed free straw, wood chips, or biodegradable weed paper.

If you already have raised beds filled with soil, fall is a great time to refresh them for the next growing season. One of the central principles of no-till gardening is to disturb the soil as little as possible. Rather than pulling out every old plant, consider leaving the roots in place when practical.

When your summer crops are done for the season, cut the plants off at the soil surface and leave their roots in the ground whenever appropriate. As the roots decompose, they contribute organic matter and help aerate the soil.  Spread approximately 1–2 inches of compost over the existing soil in your raised beds. There is no need to add potting mix or turn the compost into the soil.

After adding compost, cover the soil with an organic mulch to help protect it through the fall and winter. After applying compost and mulch, water the bed enough to moisten the compost and surrounding soil. Moisture supports the biological activity that helps break down organic matter. The soil you create will now include a diverse community of organisms, including bacteria, fungi, and earthworms. These organisms help break down organic materials and contribute to healthy soil structure.

Taking some time in the fall to establish these soil building principles will help reduce the amount of time spent in the busy spring season preparing fresh soil and allows many months for the magic of healthy soil development to occur before the first seedling is ever planted.

Tracy White-Urrutia is a University of California Cooperative Extension Master Gardener of Tuolumne County.