How are Mulch, Soil & Compost Different?

Minnesota mulch soil and compost

Topsoil, Mulch, & Compost: What’s the Difference and How to Use Them

When landscaping your yard or setting up a new garden, it’s important to know how to use certain organic materials to get the most out of your plants. Three of the most commonly used materials are mulch, compost, and topsoil.

What can Mulch do for me?

Mulch is what goes on top of soil. It is created to protect the above ground parts of the plant & will retain moisture. It will also protects your plants & trees from the extreme temperatures we see here in Minnesota. Due to the high carbon, It will stop the weeds from growing in your garden. Over time, mulch will break down and effectively become topsoil but it shouldn’t be used in lieu of topsoil. That said, while you could leave your topsoil uncovered, it is wise to cover it with mulch to avoid erosion from the rain and overheating from our hot sun.

What is Compost?

Compost is basically a form of decomposed mulch. Compost needs to be incorporated into the soil as it can turns your plain dirt into a nutrient infused soil. The benefit of compost is similar to mulch in moisture retention and insulating properties. However, it has no benefit for reducing weeds. It actually improves the soil and will promote great plant growth which in turn includes weeds. Most compost, if properly manufactured, has no weed seeds in it. They have simply been cooked out. Some varieties of manure compost with a high percentage of horse manure have many weed seeds, and it should be avoided. A balanced compost of manure has a higher percentage of cow manure, which is preferred. Cow, poultry, sheep and swine are the preferred manure composts.

Need for Topsoil?

Soil is the most complicated of the three. We are finding that it is the structure of soil that is often overlooked. Soil needs to drain well and have organics and voids for the roots and the moisture to allow root growth. Compaction of soil is a common problem as it limits the root growth. Adding compost to your soil reduces the compaction issue that we commonly see.

How do you use all 3 Together?

To use all 3 for the best plant growth you will start by laying a base level of topsoil that is enriched with compost and cover it with your choice of mulch.