A common question is whether someone should use compost or topsoil for their gardening project. As a good general guideline to follow, topsoil should be used when you need to raise the absolute level of your ground while compost should be used to make your soil healthier.
Topsoil is just like it sounds: the very top portion of the ground. It is important to have a high-quality soil for the top six to 12 inches of your garden or lawn since this is where most of a plants' roots live. At a high level, a good topsoil will provide both structure and nutrients for plant roots. We have created a topsoil buying guide to help you find a high-quality topsoil.
Compost is decomposed matter that provides nutrients (and important microscopic life that helps keep your soil healthy in the near and longer-term!). We have also create a compost buying guide to help you find a compost that fits your needs.
When you already have soil in place for your garden, it's generally cheaper, easier, and of equal quality to just use compost to make that existing soil healthier (vs removing the existing soil and replacing it with a higher quality topsoil). While compost is truly amazing, it generally has to be combined with other minerals--like sand, silt, and/or clay--to provide a sufficient structure for roots.
Of course, there are always exceptions to a general rule-of-thumb. For example, if your yard is filled mainly with rocks or your soil is so hard that you can't put a shovel it in, then compost may not be sufficient by itself to help you grow in the area. For these cases or any others, please feel free to reach out and we'll be happy to discuss your project with you.