Optimal Soil-to-Compost Ratio for Raised Beds


One strategy to prevent digging in heavy clay, rocky, or sandy soil is to construct raised beds for your plants. In order to get the most out of the sunshine that is available, it is possible to create a raised bed in an urban garden directly on top of a concrete slab. Gardeners who have trouble moving about may continue their hobby with the assistance of raised beds, which bring the soil and plants to a more convenient height. Even if it’s not too difficult to construct a raised bed, you will still need to fill it with soil and compost when you’re done.

Soil Mixes for Raised Beds

The traditional soil-based mixture for a raised bed consists of garden soil, compost, and sharp sand all mixed together in equal quantities. You may use perlite instead of sand to assist lighten the soil if it is heavy clay, which is the kind of soil you have. If, on the other hand, the soil in your garden is sandy, a combination of one part soil and two parts compost will provide the additional organic matter that your plants need to grow. If you don’t have access to garden soil, you may easily start a garden by combining equal parts bagged topsoil and compost. This requires the least amount of work on your part.

How Much Do You Need?

It takes one cubic yard of soil mix to completely fill a raised bed that is four feet wide by eight feet long and ten inches high. A cubic yard equals 27 cubic feet. To put this quantity into perspective, a trash can with a capacity of 30 gallons may store between 4 and 5 cubic feet of material. Therefore, to fill your raised bed, you will need around two garbage cans’ worth of garden soil, compost, and sand. Even though it may seem like a lot of dirt, if you create your own compost pile within the raised bed in the autumn using manure, grass clippings, dried leaves, and food wastes, your raised bed will be ready for planting in the spring. The compost pile should be at least three feet tall.