in the dirt, urban plot
how to build a straw bale compost
Sep
following the instructions from Eliot Coleman’s The New Organic Grower, we have built a compost bin out of straw bales. this method is beneficial because the straw bales contain the heat needed for the materials to break down, while also allowing air flow. we have set up two bins side by side, but the first one just continues to diminish (as it breaks down), so we just keep adding to that one. we also purchased some compost inoculate to add the beneficial microorganisms to the pile and help speed up the decomposition process.
where do we get enough organic material? the compost is a mix of brown (carbon) and green (nitrogen). the green – we compost all on-farm organic waste, including grass clippings and weeds (sans seeds) and spink gets about 50 lbs. of kitchen scraps from his company every day (keeping usable material out of the landfill while making us quality soil amendments!). the kitchen scraps are primarily fruits and veggies (lots of pineapple tops and skins – not sure how well that will decompose) and coffee grounds. we add straw for carbon source and try to mix it together so it all breaks down nicely. we plan to use the compost on the farm to amend the soil.
neat idea, especially in regards to insulation and heat retention. so, in effect the strawbales are the walls or structure of the compost bin, right?
i’m going to consider employing this method of construction @ my home (5′ X 15′ area) instead a wood or pallet frame. eventhough it will reduce to the volume i am able to compost, i think the heat retention will more than make up for it. any thoughts?
where did you purchase your compost inoculate?
Hi John,
Annabel here….thanks for visiting our blog! The strawbale compost has worked pretty well for us so far. Every time we think it’s full, the amount reduces even further, so we just keep adding organic scraps. We’ve only been using this method since June and we haven’t harvested any compost yet, so we can only speculate about heat retention, though that is what Eliot Coleman says happens and our pile seems pretty hot. I think 5′ x 15′ sounds pretty large. Where will you get enough material to fill that area? I would recommend something smaller or just breaking up the 15′ into 5′ x 5′ sections and then rotating the piles. Let me know what you end up deciding.
We got the compost inoculant from Peaceful Valley (along with our garlic order). There is a place in Hartville that sells it – Ohio Earth Food, but we couldn’t make it down there given their hours of operation. Good luck!
Hi Annabel: thanks for the quick response. The 15′ X 5′ area I was speaking of is the total amount of space I have available for composting, hemmed in by a fence and my house. The actual contained area will be much smaller, likely about 3′ X 9′ including the width of 3 bales, so roughly 3′ X 4.5′ X 2.5′ (height) of compostable area. Our current bin is roughly 3x3x3′ and we continually run out of room, esp for leaves in the fall plus not much decomposes during the winter even though i’ve tried to insulate our plastic bin w/ bags of leaves…
where did you purchase your bales?
thanks again; this is very helpful!
Oh, that size sounds more reasonable. We got our straw from a guy named Harold in Columbia Station. We found him on craigslist. $2/bale, but not sure how to contact him…..suggest checking craigslist. going rate is about $2-4/bale depending on where you get it. Hope it works out well for you!