Mulch is one of the most important things for a garden. Generally, it is defined as any sort of loose material — leaves, straw, wood chips, bark, even rocks — that is spread over the soil in a garden. Mulch is vital to sustainable gardening because it prevents the soil from drying out or eroding, provides habitat for soil life and microbes, and ultimately breaks down to form a nutrient-rich humus layer on the surface of the soil.

While things like leaves or grass clippings, both great mulch material, often come free and in great quantities, sometimes the issue is that we don’t need it all at once. That’s when a mulch pit can really come in handy. Rather than sending all that mulch away or over-stacking it on the garden (no more than four inches), store it away in a pit. Mulch pits are a great addition to gardens, and in the right hands, they can really make difference to how things grow.

What is a Mulch Pit?

Well, now that we’ve deciphered what mulch is, it isn’t that hard to put together what a mulch pit is: It’s a pit full of mulch. There are several purposes for creating mulch pits. If the hole is lined with plastic, filled with carbon-rich mulch material and covered with a tarp (kept dry), it can be stored for quite some time without turning into compost. If the hole is dug, left unlined and uncovered, it can work as a great sponge for water and a feed trough for the plants that surround it. Mulch pits are also often used for cleaning gray water because, after a while, they become rich in microorganisms that will munch away on the impurities in gray waste water.

How to Make a Mulch Pit

The crux of the mulch pit is basically the size. Many people will size them similarly to a compost bin (roughly three feet by three feet and about two or three feet deep). But, there are other options. Magic circles are a great way to grow very hungry plants like bananas around a mulch pit. They are circles about six feet across and three feet deep, with the excavated soil forming a ring around the hole. Fill the hole with mulch, and it will store water as well as rot down to provide nutrients to the plants cultivated in the ring around it. These are also great destinations for large debris that wouldn’t spread well over a garden. Or, it can be a trench that weaves and winds through the garden, making sure that plants always have access to moisture.

Why You Should Include One in the Garden

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Mulch pits are a common and extremely useful way to dispose of mass compostable waste, especially carbon-rich (boxes, paper, leaves, sticks) matter that won’t get stinky like nitrogen-rich (food, manure, fresh grass clippings) will. It can be a long trench that eventually turns into very rich planting space, or it can be short-term storage for mulch material. Stick it in the pit while the getting is good then apply it to the beds when the goods grow thin. Or, a personal favorite, mulch pits are a really lazy way of composting: One just throws everything into a big hole and let Mother Nature do her thing at her own speed, which beats the hell out of turning compost.

One thing is for sure, and that is mulch pits are multi-purpose. They provide soil fertility. They store water for plants. They store mulch for garden beds. They clean up gray water. They give us a place to deal with chunks of organic waste, like old stumps or tree branches. They are easy to make, and they have a place in any garden large enough to handle one. The benefits are just too great to ignore.

Lead image source: KaliAntye/Shutterstock