Build a Healthy Soil
Starting a new landscape is the perfect opportunity to improve the soil before planting new plants. Healthy soil is essential to a healthy garden because it helps your plants and landscaping thrive. A healthy soil is alive and is made up of minerals, living and dead plant material, fungus, bacteria, mycorrhizae, insects, and billions of micro-organisms.
To learn more about the value of soil, we recommend:
- Soil Matters: From Backyard to Backcountry, Bay Nature Magazine
- Sustainable Gardening—Building Healthy Soil (PDF), Contra Costa UC Master Gardener Program
Preparing Soil for a New Landscape
Whether you recently removed your lawn, or you have bare soil, incorporating soil amendment (compost) into the soil with a rototiller will dramatically improve your landscape. Follow these steps:
- Wet the area two days before so that the soil is moist down at least three inches. This may require you to run the sprinkles several times to allow it to soak in.
- Review all safety precautions before using the rototiller.
- Rototill the entire area to be re-landscaped. This may require going over the entire area two times in opposite directions.
- Install quality soil amendment (compost) and apply a 3-inch layer on top of the entire area to be re-landscaped. See below for more information on how much to buy and where to purchase.
- Mix in the soil amendment by rototilling the entire area to a depth of 6 inches or more. This may require going over the area two times in opposite directions.
- Break up large dirt clods as needed and rake the area to your desired contour.
How much soil amendment do I need?
As mentioned above, it's best to apply a 3-inch layer of soil amendment. For every 100 sq. ft. of area, you will need about 1 cubic yard of soil amendment. For example, a 500 square foot area would need 5 cubic yards of soil amendment. Please note: A standard half-ton pickup truck will hold two to three cubic yards of soil amendment, so if possible delivery may be the best option.
Where to purchase?
View our list of local landscape supply companies that sell (and some that deliver) soil amendment by the cubic yard.
Improving Soil in an Existing Planted Area
If you have an existing planting area that already has shrubs, trees and other plants, you can improve the soil over time by following these steps:
- Remove any existing mulch by gently raking it away.
- Using a heavy metal rake, scrape the top of the soil enough to break up any crust.
- Apply 1-2 inches of soil amendment to the top of the soil. Be sure to leave room around your plants and avoid applying the soil amendment right up against the plant base.
- Re-apply the existing mulch and add new mulch as needed.