Thursday, December 24, 2009

Hype about worms destroying old growth forests and reality about red wigglers

I receive many questions about compost worms escaping from the worm bin to destroy forests. IF you read the story, it relates to worms introduced by fishermen dumping their bait in the forested areas around lakes.

The fact is: earthworms can harm some environments. In nature nothing is as simple as all good or all bad. The earthworm's ability to tunnel through the soil and make passageways for air and water, to decompose organic material and release its nutrients, and essentially "till" the soil is good news for farmers and gardeners. They are actively growing crops that are continually replanted, and where the soil is continually amended with other nutrients (compost or mulch). Earthworms essentially prepare the soil for us. Here the presence of a lot of worms is good.

On the other hand, in forest ecosystems an overabundance of earthworms rapidly decompose the spongy layer of leaves and plant matter that makes up the forest floor and it is consumed faster than it is replaced by falling leaves and other decay. This 'duff' layer is essential to understory development (tree seedlings, wildflowers, ferns, etc.). Without the duff layer, invasive plants have an opportunity to gain a foothold. Here an overabundance of worms can result in harm.

The underlying (no pun intended) problem is that earthworms are not native to most northern parts of the country, including New England. Earthworms in this area were killed during the ice age. The earthworms in your garden are species from Europe that may have arrived with the Colonists (in soil used as ship ballast or with plants) or gardeners spreading compost or mulch from away.

I am not concerned about my red wigglers. Although I recognize they are non-native, they are not hardy in northern climes and probably won't survive our long Maine winter without a source of heat (hot compost pile). Here in Scarborough, my worms would have to cross Route 1 and the Maine Turnpike to reach an old growth forest (

Nevertheless, we should use good worm management to limit the potential for a problem. If you live in an area that abuts old growth forest, you should locate your outdoor compost pile and garden away from the woods. The University of Minnesota, which has been a leader in researching and spreading awareness of the problem, has some recommendations (and lots of helpful info) in their Great Lakes Worm Watch.

Merry Christmas!


Saturday, December 5, 2009

Starting your worm bin

Your worms have arrived. Hooray! Now what? I get this question a lot, so here are the step-by-step instructions to get your bin started. I am doing this outside to be sure we have enough light for the photos. I typically start new bins indoors.

Step 1. Gather your materials. You will need your bin, your worms, some food, and newspaper. You should have about half as much food as you have worms. I’m starting with a pound of worms and a half pound of food (such as old salad greens, coffee grounds, tea bags, egg shells, and banana peels).

Step 2. Put your food in first. Food always goes in the bottom of your worm bin. Your worms will be able to find the food more easily, it will break down faster, and it won’t attract fruit flies. Start feeding in one corner and your worms will completely cover the food.
Step 3. Add your worms. Put them directly on top of the food. Your worms will eat this food as it breaks down and you want them tin contact with it. The next time I feed them, I will put the food in the adjacent corner (the empty corner on the right side of the photo).

Step 4 Add newspaper. Now you fill your bin with shredded newspaper (or other bedding). That is all you need to start your bin. No soil is necessary!

Step 5. Fill your bin to within about 3-4 inches of the top (push down gently to be sure the newspaper is in contact with the worms). You’re finished! Mark your bin with a sticky note where the worms are.

Feed in the adjacent (in the case of my photo) counter-clockwise corner next. In the case of this bin, I will again add ½ pound of food next week ( the same in the 3rd and 4th corners the following weeks). When I get back to my original corner, I will feed ¾ pound of food in the corners for the following 4 weeks. When I complete this cycle, I will add 1 pound of food per week. At this point your worms should be close to double the number you originally received and able to keep up.

Remember, don’t overfeed and always put the food on the bottom under the worms. Then cover with newspaper. If you smell rotting food or see mold or fungus in your bin) add less food until the worms catch up.