How Much Compost Should You Use?

Composting can be a wonderful hobby to take on, but for many, it is also a way of life. Using the compost process is excellent for your lawn and for the Earth. Capable of suppressing plant disease, improving soil structure, and degrading specific pollutants, compost is used by gardeners all over the world in order to practice a positive, environmentally friendly way of gardening.

While composting is extremely beneficial, it is an intricate process that requires just as much time, knowledge, and skill as other gardening practices. One question many gardeners ask is how much compost they should use. This can be a tricky question because it usually depends on its use and the characteristics of the native soil.

The amount needed can vary, and while adding any amount will be beneficial, there is an amount within a fairly broad range which will yield optimum benefits. For example, new lawns, established lawns, and gardens that are both new and established require different amounts of compost. There are various ways to determine how much compost you’ll need, but the first factor you have to consider is the area of the soil you’ll be amending with compost.

In your garden, for example, if you plan on using 1 cubic foot bags, one good rule of thumb to determine the proper coverage rate is to multiply the length by the width of your garden to calculate the area. Next, take the area and divide it by 10 to find the minimum number of bags you’ll need. Double that number of bags if you have particularly high clay or sand content. Let’s say you have built a 4 foot by 8 foot raised bed garden and filled it with topsoil or commercial potting mix. Adding 3 bags of compost will make a dramatic difference in your results. If you are using poorer soil for your initial fill of the bed, you could add 6-8 bags for the best benefit.

Also, in general, it’s ideal to mix your compost deep enough that the roots of your plants will be surrounded by the mixed soil and compost. This can be done with a rototiller or with a hand rake, scrabler, or cultivator.

For established lawns, spreading a layer of about 1/4 inch will give good results, although an inch or more would not be too much. Although there are machines made to top dress lawns with compost, an easy way is to hand broadcast with a standard round-pointed shovel.

Be sure to measure the area you need to amend with compost, and talk to a local nursery or compost professional to make sure you use the proper amount for your specific lawn or garden. By knowing a few general guidelines such as these to base your amounts on, you’ll not go wrong.

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