compost bins

Compost is an essential component of urban gardening.  The Garden of Union ran a large  (14 ton annually) system in cooperation with the Park Slope Food Coop from the beginning and to the 2021 pandemic. Claudia Joseph was the site coordinator from 2005 -2013 and helped design the expanded system as the PSFC rapidly gained members. The bins were designed and constructed by Open Road NY.  This compost system was open to all members, whether they gardened or not, as well as neighbors and the general public.

The Old Stone House  partnered with Brooklyn Botanic Garden in 2009 to construct 3 mega-bins at MS 51.  We used these for our annual pumpkin smash and in cooperation with restaurants as a study for the MS 51 Science Fair. Cafe Martin supplied buckets of coffee, daily.
The Old Stone House and PSFC built 3 custom, extra-sturdy bins and started receiving material in the OSH educational Farm garden in May 2014.  A neighborhood compost club was started in 2016. Thanks to a grant from Citizen’s Committee for NYC and major support from the Park Slope Food Coop, compost material enriches the gardens continually. Special thanks to our designer/carpenters Lloyd Hicks and Tom Twente and to Joe Holtz and Phil Collosi at PSFC.

Nitrogen rich material
Carbon rich material
Chop or shred all raw materials.
Mix the brown and green materials together in equal parts. (Many books say 80/20 but you can tinker with the ratio).

Nitrogen is in all fresh organic material – green leaves, grass, weeds and food scraps. It is present in fresh coffee grounds and manure.
Carbon rich material includes brown leaves, sawdust, paper and nut husks. Nitrogen moves into the air as green material dries out leaving primarily carbon material behind.

Nitrogen is often referred to as “green” material and carbon as “brown”.  This is a general guideline and there are some exceptions.  Another way to think of it is that nitrogen is “wet” and carbon is “dry” organic material.

Trouble-shooting Guide

Use additional carbon material, as necessary for odor and insect control.

Bugs = too much nitrogen or a wet condition.
Odor? not enough air – turn the pile or aerate with a corkscrew. Or it could be too much nitrogen material in the mix.

No break-down/no heat?  Too much carbon or not chopped enough.  May need water.

Whole foods will remain whole for many months. Entry points for bacteria are key to decomposition. The more you chop and turn, the faster decomposition happens.

What not to compost:
Anything greasy
Feces of animals that eat meat
Large items that do not break down: Wheat grass mats, flower arrangements, coconut shells
Starch – can be used but does not benefit the system.
Egg shells look like litter in the landscape, you may wish to grind them first.
Soil – use it in the landscape.

Although most materials will decompose eventually, in urban systems, omit all meat and eggs.  Avocado pits do not break down and can be problematic.
To maintain hygienic systems in urban areas, be cautious and monitor your bin daily.

Turning will speed the decomposition process and help control odor by introducing air into the system.

When you are finished adding material, always cover it with a layer of carbon material so that nitrogen material is not visible. This inhibits both odor and insect activity.

There is always another point to add – observe your system often!

Review: An even amount of mixed browns and greens. 
The more you chop and mix the faster it works.
 No greasy stuff or starch.
 Some moisture and air! A square of cardboard on top helps to keep insects away.


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