Garden members are encouraged to use the four bins located next to the Wayne Avenue gate to dispose of plant materials from the garden. You are also invited to bring kitchen scraps from your house to add to the pile. Each bin has a sign saying one of three things: “New Materials Here,” “No New Materials,” or “Finished Compost, Take Some.” The signs will move as the compost gets shifted from bin to bin.

You can put materials in any bin with a “New Materials Here” sign. If you see a bin with the “Finished Compost” sign, feel free to take some for your bed. If you want to screen it first, you can use the compost screener that will be near the bins. Any organic material you screen out can go back into the active compost.

What should go into the compost?

Materials that are always welcome

• Healthy (not diseased) Plants from Your Garden Bed. All should go into the compost. Please don’t put them in the trash.
• Most Kitchen Waste: Vegetable peels and cores, egg shells, coffee grounds, used tea leaves, the compostable produce bags used at Weavers Way. Whole fruits, tubers, onions and cabbage heads decompose better if they are cut into smaller pieces (or at least punctured or crushed) before they go in.
• Weeds From the Garden: Most weeds are fine and, with some exceptions (see below), should go into the compost.

Materials that can be added as needed to manage the piles:

• Wood Chips: Wood chips that we don’t use for mulch can be used in the compost bit-by-bit.
• Straw or Salt Hay: These can be composted, but, like wood chips, they take a long time. Cut them up before putting them in.
• Raked leaves: We can sometimes use them. If you bring some, leave them in bags to be added as needed. Right now we have several bags of shredded leaves to use.
• Manures: Ask first! Wonderful addition to a pile, but need to be carefully balanced with “brown” materials. If you have access to (horse, cow, sheep, goat, etc.) manure and could bring some, let me know at maintenance@hansberrygarden.org. We can sometimes use small amounts.

PLEASE BREAK UP VINY OR TOUGH  MATERIALS BEFORE ADDING TO BINS.

Whole plants (e.g. tomato plants, collards or cabbages), vines, and woody stems or branches decompose very slowly and make it hard to turn the compost. The more you damage them, the faster they will decompose and the safer the backs of the people turning the compost will be.

What Should Stay out of the Compost?

• Inorganic Materials! No plastic of any kind, including plant pots and labels, Also no bottle caps, glass shards, running shoes, or eyeglasses (yes, I have found all of these items in the compost at one time or another).
• Non-Vegetable Kitchen Waste (other than eggshells, which we do want): No dairy or meat residues (e.g. bones), nothing greasy or oily, no dry pet food, no “compostable” plastic-like cups or plates (these are compostable only in industrial compost that reaches extremely high temperatures).
• Certain Highly Invasive Weeds:
  
  • Japanese Knotweed. Even a small piece can take root in a compost pile.  Poison ivy is never okay (but I probably didn’t need to say that).
  • Canadian thistle if there are pieces of the rhizome attached. If in doubt, leave it out.
• Large Amounts of Vines and Woody Stems: Small amounts are fine, as long as they are cut up before they go into the pile (see above). Otherwise they should go into the trash.
• Diseased Plants from Your Garden Bed: This is important when we near the end of the season when it will be hard to maintain a high temperature in the compost piles.
• Weeds with Seed Heads after Mid-September: During most of the season the temperature of the pile should be high enough to kill whatever seeds are there. By mid-September the weeds are much seedier, and it might not be possible to maintain the temperature, so best to leave them out.

How Else Can I Help With the Compost?

• Help maintain the balance of “green” and “brown” materials.
  “Green” materials generally include moist things like kitchen scraps (even if they are brown in color, like coffee grounds or potato peels) and fresh leaves of herbaceous plants like garden trimmings, grass, and weeds.
  “Brown” materials include drier things like wood chips, raked leaves, straw or hay, and pine needles (even green ones!).
  
  If you bring brown, woody materials and you see there are a lot in the compost already, leave yours beside the bins to be added later.
  
  If you add a lot of green material, please add brown leaves or wood chips from the pile beside the beds. Ideally, add about the same amount of brown to match the green you just added. If there’s nothing there to add, don’t worry about it.
  
• Help turn the compost
  During the summer the compost needs to be shifted from one bin to another at least once a week. The timing depends on the temperature of the compost. If you are interested in turning the compost on a regular basis, contact maintenance@hansberrygarden.org (or just talk to me when you see me in the garden).
  
• Cut or chop up large vines, branches, etc. that have been left by the compost bins. Volunteer efforts sometime yield more viny weeds and branches than we can handle in a day. If you see a pile of these near the compost bin, you can always grab a pair of clippers or loppers and chop away.

Curious About Compost? Here are the Nerdy Answers to Your Compost Questions.

What is a “well-maintained” compost pile?

A well-maintained compost pile is one that facilitates the breakdown of organic matter by encouraging the growth of the aerobic (oxygen loving) microbes. This is achieved by keeping an appropriate mix of “brown” and “green” materials, and by turning the pile regularly. To put it another way, a well-maintained compost pile feeds the right kind of garbage to the right kind of organisms (from worms and bugs to fungi and bacteria) to get them to make plant food, while killing off the wrong kind of fungi and bacteria.

What do they mean by “brown” and “green” materials? (The science-y explanation)

Microbes in a compost pile need to feed on two chemical elements: carbon and nitrogen (C and N). All organic matter contains those two elements, but in different ratios.  The microbes we want to encourage thrive in a C/N ratio of about 30/1 (30 parts carbon to one part nitrogen). If there is too much nitrogen the pile produces ammonia gas, gets slimy and smelly, and can become toxic to the desired microbes.  Too much carbon and the microbes can’t grow or reproduce very quickly. The pile will take a long time to break down, and may contain weed seeds and plant pathogens.

“Brown” materials are things that have a C/N ratio above 30/1; “green” materials have a C/N ratio below that. However, the color terms are somewhat misleading. It’s true that many nitrogen-rich materials are green in color (e.g. grass clippings at 15:1, vegetable scraps 20:1) and most carbon-rich materials are brown (e.g. wood chips at 400:1 or egg shells at 100:1). However, some brown colored materials, like cow manure and coffee grounds (15:1 and 25:1 respectively), are chemically “green.”  Green pine needles have a ratio of 60:1, making them chemically “brown.”  To complicate matters further, in some materials (e.g. wood chips), the carbon is harder to break down, so they may, effectively, have a lower ratio.

By this time, you may be thinking: “I can’t sit around all day counting molecules! How do you manage a compost pile??? The answer is: Don’t worry about it too much, but try to have about a 50/50 mix of “greens” and “browns.” During the height of summer, we tend to have a lot of green, so need to add some brown. Other times we have too much brown and really need your veggie scraps. 

What is “cold” composting, what is “hot” composting?

Cold composting happens with little or no human intervention. Any pile of organic material that is not too high in nitrogen can be broken down by anaerobic microbes (microbes that can’t use oxygen) in about a year.  It’s great because it requires no effort beyond making a pile. However, it takes a long time, and weed seeds and plant pathogens that go into the pile will usually still be there at the end of the composting cycle.

Hot composting relies on aerobic (oxygen-using) microbes in a multi-stage process. It has two big advantages over cold: It is much faster, and the high temperatures kill weed seeds and fungal and bacterial pathogens. The disadvantage of hot composting (relative to cold) is that the pile has to be turned on a regular basis, so it’s a lot more work. We are aiming for hot composting.

Hot composting takes place in three phases. In the first phase a community of insects, worms, bacteria, fungi and other microorganisms that like temperatures below 105 degrees (mesophilic organisms) begin the process of breaking down materials. As they do, they generate heat. If they don’t run out of oxygen or food, the community of micro-organisms can raise the temperature of the pile high enough that only specific kinds of bacteria can survive. These thermophilic (heat loving) bacteria really like temperatures between 113 and 140 degrees. In phase two, they multiply, continuing to raise the temperature of the pile.  Most pathogenic organisms and seeds will die at around 130 or 140 degrees. If the temperature of the pile goes above 150, the thermophilic bacteria will start dying off and the temperature of the pile will drop.. Likewise, once they start to run out of fuel the temperature of the pile will drop, signaling the third phase, in which mesophilic bacteria return. Eventually all the organic matter is broken down into forms that plants can use.

What does turning the pile do?

Turning the pile does two things: It distributes material in the pile, and it breaks up anaerobic pockets, both of which make more food available to the bacteria, encouraging further growth (and more heat). If the pile gets too hot, turning the pile cools it down. If the temperature starts to drop, it makes more food available to the thermophilic bacteria, extending the hot phase of the compost. In optimal circumstances (30:1 C/N ratio, keeping a pile at about 4 cubic feet, turning whenever the pile temperature drops), we could keep the temperature at or above 140 for days at a time, and have fresh compost every three or four weeks

“Brown” materials