Vermicomposting 101

Did you know that food scraps, junk mail and paper products make up about 30% of our garbage? Would you love an easy and fun (no joke) way to reduce this garbage, plus recycle natural fibers, paper towels, and more?

Composting is a simple, non-stinky way to reduce household garbage, viable in tiny apartment living or in large households. Composting provides a practical and useful solution to waste, converting it into feed for plants while reducing our reliance on the landfills that are quickly filling up – the byproduct is moist, nutrient-rich soil, full of nitrogen, potassium, and phosphorus.

The best part is that you will take out your garbage less often and reduce the smelly component (food scraps) of your refuse in general. If you're a regular green thumb, your houseplants and your garden will love you. If you have a bit of a black thumb, your green-fingered friends will love receiving gifts of rich compost. For children, it is great exposure to saving the planet in another way, while introducing life cycles and science!

I have heard people object to composting indoors because it will attract fruit flies, roaches or mice, or simply that it smells. All of this is simply not true. If maintained properly, you can have a healthy compost bin that will satisfy your plants for a lifetime without infestations or smells.

I will talk here about indoor worm composting, or vermicompost, as it is what I am most familiar with, and practice. It’s really not as disgusting as it sounds (I once had my doubts); it doesn’t produce any noticeable smells (seriously) and it can easily be concealed, even in a tiny living situation. In no time, your compost bin will be the center of attention at parties, amazing your friends with questions, wonderment, and they will ask for worms of their own (I speak from experience).

If there is anyone who does backyard bin, non-worm composting, or anyone who also practices indoor, vermicomposting, please join in the discussion and post a comment about tips, tricks, and what you think about it.

How it works:
All worms are not created equal. For composting you need Red Wiggler or Red Earthworms, familiar to the fishing population. Your worms have one mission in life: to eat your garbage and cast (i.e. poop) it into super rich soil. Gross, right? But not a bad life’s purpose. There are other organisms in there too that help break down your garbage. But the worms, and their health, are the number one priority.

Why bother:
Other than reducing your personal waste, including food scraps, junk mail, bank statements, receipts, newspapers and more, composting helps to reduce your need for chemical (especially petroleum-based) fertilizers. When added to plants' soil, it helps loosen packed Earth, give structure to sandy soils, aid in aeration, reduce the need to water by increasing soil’s ability to retain water, and, in general, provide a happy, healthy, chemical-free home for your plants – you know exactly what is inside.

How to get started:
Space is often a challenge, especially for apartment dwellers. There are plenty of sources online that sell attractive cedar composting bins. Your guests will never know there are worms inside that side table! If you have a little more space, or don’t mind plastic, invest (all of $10 ) in a plastic storage bin with a lid. The size should equal about 1 cubic foot per person in the household. Something that can fit under the sink is perfect for a small family. Long and wide is better than a tall and narrow bin. Use a drill, or a hammer and nail to poke plenty of air holes in the lid top. (Many people tell you to puncture holes at the bottom to allow drainage and compost “tea.” I do not do this and my worms have been active and happy for just about a year now.)

Add shredded paper, food scraps and worms (about a 1 lb. ball with some compost or a large handful) to the bin, and cover it. Try to keep about a 70:30 ratio of brown matter to green matter (brown is paper and dead material; green is food scraps and young plants). About once a week, or every other week, move the material in the bin around to help with aeration. Always keep a layer of shredded paper or sawdust over the top of the pile to discourage smells and bugs. Once you stop adding new material the compost should be ready to harvest in 1 to 2 months (depending on how much is added in the last feeding).

See the links below for ordering worms.

Maintaining the bin:
The bin should be as moist as a damp sponge. An indoor temperature of 55 to 75 degrees is perfect for the worms. Keep them away from ovens, heaters or air conditioners – too cold and your worms will freeze, too hot and they'll roast. Remember, the worms create their own heat through their work.

Worms are a little like children – they are picky eaters and they like it when their caretakers chop their food. Cut food scraps into 1 to 2 inch pieces, and shred cloth and paper before adding it to the bin. This allows more surface area for the worms to eat faster.

If you need to go on vacation, don’t worry. Your worms can be left alone for about 3 to 4 weeks without any help. Before you leave, provide them with a freezer bag or two full of food scraps and distribute it evenly around the bin. If you'll be gone longer ask a friendly neighbor to feed the little guys once or twice and move things around. After such a long time without care there might be a slight smell to the bin. Follow the tips below to solve this.

How to harvest the compost:
The compost is ready when it is a deep blackish brown color, and is moist. There may be some small pieces of egg shells or paper remaining. Before you feed it to your plants, you want to separate out as many worms as possible so they can keep working for you. Because worms like it dark and warm, they are often hiding in the middle or the bottom of the container. When I harvest, I pull compost from the top and allow the worms to keep moving down. I have found that there will always be a few “sacrificial” worms – babies and eggs – that get into your final compost. That’s okay. Some folks will lay compost out to dry after this step. I just mix it with the soil, and plant.

More tips on harvesting provided in the links below.

What if it starts to smell:
The only smell your compost should have is a slight sweet pleasant earthiness of soil, and should only be noticeable when the bin is open for feeding time. If you notice an off or rotten smell while feeding the worms, or if you notice a lot worms attempting to crawl out of the bin, something is wrong.

  1. The bin may be too moist. Move the soil from the corners. Is there liquid buildup or is the compost extremely runny and muddy? Add shredded paper, especially in the corners, to absorb water and regain balance.
  2. The bin may be too dry. Worms like a little moisture, but they don’t want to drown. You can puree some veggies to add moisture, or spritz the top with some water.
  3. Infestation. Other organisms live with your worms. Most of the time they will not be noticeable. If you get an infestation follow the links below for troubleshooting tips and tricks. Most infestations, like fruit flies, are easily avoidable if you freeze scraps for 24 hours before you add them to the bin.

Tips:

  1. Try to keep a ratio of 70% brown matter (paper, wood, dried and dead plants) to 30% green matter (food scraps, young plants and wet leaves).
  2. Chop your food scraps into 1- to 2-inch pieces and shred paper and cloth before adding it to the bin. This will help the worms eat through it faster.
  3. To reduce the chances of fruit flies (eggs are often laid in items like banana peels) freeze scraps for 24 hours before adding them to your bin. I keep 1 or 2 freezer bags going and dump the contents into my bin about once a week.
  4. Give them air! Every other week or so, move the compost around to aerate it.
  5. Don’t overwhelm your worms. If you notice smells beginning to form you might be feeding them too much! Reduce the amount you feed them and add a little paper to absorb smells until they can catch up.

Items you CAN compost with your worms:

Items you CANNOT compost with your worms:

Order Worms:
The NYC Department of Sanitation’s Composting in NYCpage has an extensive listof U.S. suppliers of worms.

To read more about composting, including tips on harvesting and keeping your worms, follow these links:

The Center for the Development of Recycling
Composting Tips
EPA website on Composting
NYC Compost Project