Frequently Asked Questions

How to Get Started

Where do I put the vermicomposter? Indoors or outdoors? Which temperatures are optimum for earthworms?
Composting with earthworms operates year-around. You can place the vermicomposter either indoors or outdoors. It is important to always ensure that the earthworms have an optimal temperature of approximately 20 °C/ 68 °F as well as a correct level of moisture in the substrate. During winter you shouldn’t leave the vermicomposter without insulation, so it doesn’t freeze through. In the summer it shouldn’t be exposed to direct sunlight, to prevent water evaporation and overheating. The temperature in the vermicomposter should not drop below 5 °C/41 °F or exceed 25 °C/77 °F.
What should and shouldn’t I put into the vermicomposter?

The vermicomposter is particularly suitable for peelings and leftovers of fruit and vegetables, such as potato peels, apple cores, green tops of vegetables, etc. Don’t forget tea-bags, as earthworms often reproduce in them. Just be careful not to put in the plastic types (usually in pyramid shape sold with more expensive teas). Coffee grounds and paper coffee filters are also suitable. So are leftovers of cooked vegetables, crushed egg shells, paper napkins, dampened cardboard, dry baked goods and remainders of indoor and outdoor plants.

Do not put intensely spicy foods into your vermicomposter, such as ginger or an excessive amount of citruses, as well as milk products, meat products, bones, oils, lard and other fats.

TIP: At the beginning of the composting, don’t put remnants of stalk vegetables and potato peels into the vermicomposter. The low number of earthworms in the beginning can’t manage to process them using their enzymes and these leftovers may cause an odor.

Which earthworms are used for vermicomposting?
Special earthworms called tiger worms or California worms are bred for vermicomposting. This type of earthworm is productive consuming organic leftovers. Common garden earthworms don’t perform as well in the same conditions.
Where do I get a hatch of earthworms for my vermicomposter?
There are many websites that focus on community gardens and composting fans. can use to locate earthworm sources near you and find links to your local suppliers.
How long does it take to compost one full container?
Creating quality composts takes approximately 2-3 months. It mainly depends on the number of earthworms and the quality of “food”.
Is the composting method different at the beginning from later on?
Yes, and it’s very important to remember this. Give your earthworms enough time to settle and reproduce, don’t swamp them with food from the get go. You will know that the earthworms are well adjusted when they begin to process the food you give them more quickly and you will also be able to feed them more often.
Should I rake through the compost regularly?
Not at all. The nosy among you beware and also make your children understand this - it’s not useful to disturb the compost, particularly during the initial breeding. Add the food to the top. This prevents you from disturbing the earthworms and disrupting their homes – they only lay eggs in specific places. You can carefully rake the compost if it appears too wet or lacking air.
What should I do if I have a container full?
Once you fill one container and it looks like earthworms soon will not have anything to eat, load the next floor as well as at the start composting. Within about three weeks in, they should earthworms move, but for sure it is even check. Vermicompost from the bottom of the container can then be used as fertilizer or dry it for later.
How often should I feed the earthworms? Can I leave for a longer holiday?
A holiday is no problem. The earthworms easily manage even a two-week fasting. However they survive without food over four weeks at maximum.
How can I dilute and use worm tea?
Worm tea is an excellent liquid fertilizer for herbs and indoor plants as well as the garden. It contains high amounts of nutrients and enzymes that promote growth and help build plant resistance against pests. You can collect worm tea in a plastic or glass bottle. It’s ideal to dilute it with equal parts water. Use the diluted worm tea for watering plants or spray it on their foliage.
What should I do with excess vermicompost or worm tea?
Anyone who grows plants will appreciate compost and worm tea. If you can’t find anyone who could use them for gardening, use the compost to fertilize trees, bushes or even planters in public spaces. Likewise with the worm tea.


Why did my earthworms die?

It may be because of excess moisture in the vermicomposter. Excess moisture by itself shouldn’t hurt earthworms, but the problem may be lack of oxygen related to high moisture levels.

It may be because of decaying food. Moldy bio-waste in itself also shouldn’t kill earthworms. But should you find moldy food leftovers in the vermicomposter, remove them.

It may possibly be that the earthworms are starving. Earthworms may starve and die after only several weeks without a food supply.

If you managed to compost your earthworms, don’t panic. Try again with a new hatch of earthworms!

I’m finding earthworms in the collecting container, outside the composter. What’s wrong?
The earthworms shouldn’t be crawling into the collecting container on their own, just as they shouldn’t be outside the vermicomposter. If they do, it means they don’t like something inside the container. It could be excess food, so take some away. It could be the lack of air. Check that the moisture level in the vermicomposter isn’t too high and whether the vermicomposter has enough air vents and possibly make some more.
How do I handle fruit flies?

Fruit flies (together with other organisms) are a part of vermicomposting to a lesser or greater extent. We can avoid reproduction of fruit flies in your vermicomposter by covering the surface of the compost with shredded paper, cardboard, newspapers or a paper bag. You can cover the newly added food a little or possibly cover the surface with already processed compost.

You can also try to create one of the recommended traps. For example, you can put a piece of banana at the bottom of a jar, create a paper cone with a tiny opening and place it point down into the glass, sealing around the edges. Or mix 3 tablespoons of water, 1 tablespoon of vinegar, 4 drops of dishwashing liquid and a pinch of baking yeast and place a container with this mix near the vermicomposter. You can also get a carnivorous plant.

You can get rid of the flies by precise closing of the container in which you place food. If the flies do hatch, they don’t get out and that can be a success. Unfortunately, you may repeatedly introduce the flies into the composter with fruit and vegetable peels containing fruit fly eggs.

If the problem persists and there is such an option, move the composter to a location where the flies won’t bother you.

What to do when the vermicomposter has an odor?
Properly maintained vermicompost doesn’t have an unpleasant odor. Should odors appear, it’s most often because the earthworms can’t manage to process all the bio waste, so lower the amount. The unprocessed bio-waste also causes high level of moisture of the composted material that then decays and smells. You can dry the contents of vermicompost with pieces of shredded paper, newspapers, cardboard or egg crates. The cause of the odor can also be remnants of stalk vegetables or potatoes. These should be introduced to the composter only after several months, when the earthworm are sufficiently active for timely processing.
What to do when there is mold in the composter?
If the contents of the vermicomposter decay or mold appears, it means that the earthworms can’t manage to process the organic waste fast enough. Remove rotten or moldy pieces from the vermicomposter, reduce the volume of kitchen waste you put into the composter and only once you see that the earthworms manage to process the food you give them, begin gradually increasing the volume of composted waste. If this is a case of already settled and reproduced earthworms and you have a larger volume of waste (large families, offices, schools), consider purchasing a second vermicomposter.
How do I decrease the moisture level in the vermicomposter?
Higher moisture is good for the production of worm tea, but an excess of anything is damaging. You can reduce moisture by adding materials that bind moisture, such as paper towels, newspaper, egg crates and similar dry material.