Not only do acorns compost, but they add an important ingredient, protein or brown compost layers, to the complete compost mix. The secret to successfully composting acorns is in the way you prepare them ahead of time.
Acorns in the Compost Pile
In order for compost ingredients to completely decay into usable compost, the pile must contain four things: green ingredients, brown ingredients, soil, and water. Green ingredients are those with more moisture, such as grass clippings or kitchen waste. The brown ingredients are drier types like branches, shredded paper, and, of course, acorns. Each ingredient adds different nutrients to the compost. When combined, they make an almost perfect soil conditioner and plant food. For a mix with a lot of green ingredients, a layer of acorns in the compost pile is an important addition, as maintaining a proper balance between browns and greens is vital.
How to Use Acorns as Compost
Using acorns as compost begins with breaking down the shells. The tough outer shell of the acorn takes years to break down naturally, but you can speed the process along. Gather all the acorns from your yard and spread them over the driveway. If you have a small amount, smash them with a hammer to crack them open and expose the meat inside. For larger, more normal acorn harvests, run them over with the car a few times until all the shells are cracked and the insides start to mash. Scrape the resulting mix from the driveway to add to the compost pile. Wait until you have a good layer of green ingredients on top of the pile, then add the mashed acorns on top. Spread them out to make an even layer, and add other dry ingredients, such as fallen leaves and shredded newspaper, to make a layer about 2 inches (5 cm.) deep. Cover this layer with about two inches (5 cm.) of soil and water the pile. Let it work for about a month, then turn the pile with a rake or shovel to allow air into the center of the heap, which will help the pile to heat up and decompose faster.