Q: My daughter’s school wants to make a compost tumbler. Do you know where I could find a 55 gallon, screw-top, food-grade drum, like a pickle or olive barrel?
A: Although they look simple to make and easy to operate, I have no confidence you’ll make much compost in a tumbler.
That doesn’t mean you shouldn’t try…it will be a good experience for the kids no matter what happens.
Handy gardeners report that it’s hard to make a durable frame to keep the barrel off the ground as you flip it.
Other gardeners report that filling the tumbler more than half-way makes it very hard to turn, with the contents just “flopping” from end to end or side to side, without much mixing.
Just as in a compost pile, the mixture inside your barrel must have the correct ratio of green material to brown. If not, no compost is made.
Don’t forget that the volume of materials you put in will result in a much smaller amount of finished compost. In my experience, you’ll get 20% or less of the original volume. A 55 gallon drum, half-filled, might yield a shoebox of compost.
Although less sexy and technological, simple compost piles at least 4′ x 6′ x 4′ yield the most “brown gold” for the least work.