My Favorite Tips for Successful Composting
- Tend to your Compost every 1-2 weeks for best results. In a perfect world, you would turn the whole pile but that has never been feasible for me. I “stir the pile.” I jab my spade fork in as deep as possible and stir. The whole pile should move. I have a hose and get moisture down into the pile. I move the spade fork 12” over and repeat until the pile is sufficiently “stirred”. I stir my pile before adding a lot of material. The piles at Kihei were very dry; compost should be damp but not dry. If you tend to them frequently, the fork goes in easy, sometimes steam comes up, the rodents stay away and it takes just a few minutes per pile.
- Breaking the Structure of Material — You donʻt have to cut everything into tiny pieces to add to the pile. It will compost faster but it might not be practical to do each time. What is encouraged is to break down the structure of the material. We had lots of stacks of paper plates and stacked cups from our harvest parties. Stacked they are not easy to break down; single items scrunched work much better. Stomp on dried leaves, fold up branches (I can take a big branch of a pigeon pea and fold it up, breaking the rigid structure to small size in a few seconds), and spread out the material. I actually like leaving a few branches (< 1” diameter) long in the pile as they help the stirring to move everything around and let the air in.
- Adding Layers — The classic composting advice is to add material in layers of 1 part green to 2 parts brown. This is not precise science but do think in terms of browns and greens. Greens are things that were recently living and growing — grass clippings, weeds, recent cut branches, kitchen scraps and live plant material. Browns are branches, dried leaves, paper plates and shredded paper. Yes, if you leave greens in the sun, they turn brown. Do this if you have too many greens. Composting is much more effective with a nice mix. The top layer is usually browns to keep rodents and flies away. You should not create any layer too thick that it will totally compact and be impermeable. I like thinking that the layer should cover the previous layer so it canʻt be seen – about 3″ max unless you have dry fluffy leaves. Be really careful with lawn clippings, thick vines and shredded paper as a thick layer can stop the composting process. For example, there was some hay bale material in the Kihei Elementary bins but the chunks were not broken up enough… it formed a thick mat that did not let air or water through. Composters (i.e. fungus, bacteria and invertebrates – “FBI” ) do not work in an anaerobic or dry environment!
- Label your Bins: If you are fortunate enough to have multiple bins, label them! Otherwise you may have lots of bins but nothing is ready. You must label your bins so everyone knows where to add material. I recommend the following signs (maybe have 2 of each): ADD LARGE MATTER HERE, ADD MATTER HERE, RESTING and READY TO SIFT. For Kihei Elementary Iʻm going to laminate 8×11 sheets, put in plastic sleeves with holes so that they can be zip tied to each bin. Painted signs work well too! The signs can be moved from bin to bin as the composting process evolves.
I like keeping one bin for bigger items that take longer to break down. Think palm branches, evil weeds, papaya or sugar cane stalks, branches > 1” diameter. Please note that is is still good to include a good mix of greens and browns. Also throw in an occasional layer of compost to really get it working. If you donʻt have enough space or bins, then I recommend removing this material from the site.
This is where the majority of items are added from the garden and kitchen. This is a very active pile that goes up and down… process it and add, process and add. Decomposition is happening! How do you know when to change the sign to “RESTING”? If you are maintaining your piles and adding material in layers, you will reach a point where the bin is perpetually 3/4 to full. You can add layers but it never goes below the 3/4 full mark. That would be the time to let it rest. In my home garden, where I only have 1 official bin, at this point I remove the wire that constitutes the “bin” and move it to a new place. I let the pile rest a few months before I start to use. In the photo above, Iʻm almost ready to let it rest.
During resting, continue to stir and water, but quit adding new material. You may need to stir less frequently. When the bin is about 1/2 full (or half empty) and you can dig down about 6” and find beautiful compost then it is ready for sifting. The outside may still show a lot of debris and dry material. This is a great time for students to observe the composting process. Smell how beautiful it smells, observe the different types of bugs; they are part of the composting process. The rest period should be no more than about 3 months.
Sifting is a great workday activity. Make sure volunteers wear gloves and close-toed shoes. In my experience, centipedes are inevitable (Make a game out of counting them and carefully move them over to your add pile so they can keep working) and hope you donʻt see any rodents. Place a sifter over a wheelbarrow. Start taking material from the compost pile and into the sifter. Break up big chunks of compost and let the beautiful compost collect in the wheelbarrow. Two people hold each end of the sifter and move back and forth (slow shake) is the most effective way to process quickly. Ideally disperse composted material directly around the garden or create a “ READY TO USE” pile. At first it seems like there is more being left in sifter than is composted but that changes fast. Toss the unsifted material back into one of your ADD piles; the addition of compost will get those working even better.
If youʻve been filling all your bins for awhile like we have at Kihei El, there may be an enormous amount of good compost on the ground around the bins. Get out your shovel and collect it for use in the garden beds.