Hay-Bale Compost

Hay-bale, slow-cook compost pile

One of our readers noticed this picture on our website of a hay-bale compost bin and was curious about making one. This kind of compost pile is ideal for the following conditions:

• You have plenty of room (depending on size of hay bales, its "footprint" can be as big as 5' x 8').
• You have enough time to leave it alone for several months while it slowly decomposes.

If your situation meets these criteria, here's how to make one: 

 Make a box of hay-bales.

You can start this hay-bale compost any time of year but its ideal if you make it in the fall as you're putting your garden to sleep for the winter and will have large quantities of plant-matter. Lay your hay-bales in a rectangle, one layer high. As you pull up your squash, corn, tomatoes etc toss them in the pile. If you're putting in "woody" material or thick stalks (corn, sunflower etc) they will break down faster if you cut them into smaller pieces with a machete or pruners. Mix in some rotting apples or kitchen scraps (vegetable matter only please) to attract red wriggler composting worms. Since the pile will shrink by at least half over the winter, pile it high, stomping it down as you go. Put a tarp over the pile once the winter rains start and by spring you'll have a beautiful pile of organic matter to nourish the new plants you're transplanting into the garden.

Sifted compost to nourish transplants - put a big handful in as you plant them.

Do not put in grasses from your garden that can grow from bits of their roots. For example: Bermuda grass or Quack grass etc. This is a slow-cook pile and its not hot enough to kill these weeds. If you put them in the compost you will then spread them all through your garden when you "harvest" the compost!

Sifter with hinged legs. It can be moved to sift different piles of material in your garden.

One last step... In order to separate out the composted goodies from the materials that didn't break down over the winter, you'll need to make a sifter. Chris built the one above from lumber scraps we had leftover from other projects and some half-inch "hardware cloth" (wire mesh). The legs are attached with hinges so it can be folded up to move and also set at different angles. A simpler sifter can be made to fit over your wheelbarrow or garden cart - half-inch holes are ideal. Using our sifter, we place a tarp below it. You'll find it will work best if you use a spade-fork to break the compost pile into smaller clumps before tossing them onto the sifter.


The hay bales rot and decompose throughout the whole winter and make incredible sheet-mulch to put around your transplants in the spring. You'll notice as you peel off the 2-3 inch "flakes" (they're pretty gooey by spring-time!) that they are full of red worms, their eggs and castings. Your spring garden now will be infused with a new, healthy population of these mini-livestock. 

You will likely have many "volunteers" from the seeds of the plants you threw into your compost pile in the fall. Don't worry! You can easily weed them out if they come up in your garden beds.

Unsung heroes!

Please also read:

Herbicide Contamination in Manure, Compost and Grass Clippings?

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