[Community_garden] Lime, worms and flies

[Don Boekelheide]

Hi all,

On worms, lime, fruitflies etc

Bottom line - I have worm compost and like it so much
that's all we use at the house anymore. And, I don't
use lime in my bin.

Mike's reference to Mary Applehof is very apt, she was
a wonderful resource, and 'Worms Eat My Garbage' is an
enduring classic.

Cordalie's reference on calcium carbonate is worth
visiting, if a little technical (you might also want
to check Wiki's limestone page). For what it's worth,
here are a couple of basics (so to speak). 

Lime comes in different formulations. Calcium
carbonate is indeed often the active ingredient in
lime (ground up limestone) sold in the garden center.
Often, this kind of lime is 'pelleted'  (gray-brown
little chunks, like rocky all bran cereal). However,
'lime' can also be calcium hydroxide (aka 'slaked' or
'hydrated' lime), sold as a white fine powder.
Gardeners and farmers use both kinds of lime to make
soil less acidic - ground limestone is easier to use,
slaked lime works faster but is unpleasant to work
with.

You may also find calcium oxide, or 'quicklime' -
which is so basic (non-acidic) it can 'burn' your
hands (like lye). It's bad news, don't use it for your
worm bin - even though it is used to treat sewage.

In all cases, the way lime works is by dehydrating the
maggots and by making things so basic everything dies.
And, of course, if it kills maggots it can kill your
worms. If you dust the maggoty areas with powdered
lime, the maggots may die while the worms crawl for
cover deeper in the bin - but you run a risk.

An aside on wood ashes. It isn't lime - according to
Clemson University research, ashes are highly variable
depending on the wood and kind of fire, but have
roughly 35% calcium carbonate, and lots of other
materials, too. Gardeners value ashes because of the
potassium (K - third number on the fertilizer bag)
they contain, plus the trace elements. However, Mike
is right that ashes also make soil (and your bin) less
acidic - in fact, they are even more powerful than
lime! For that reason, gardeners use them sparingly.
Ashes would work like lime in your buggy wormbin, but
with the same problem (what kills maggots kills
worms).

Interestingly, coffee grounds would do the opposite of
lime chemically, making conditions too acidic. But
worms don't like them, either - I did an experimental
trial of large amounts of coffeegrounds as sole
foodstock, with newspaper as bedding, in wormbins, and
the results were a complete bust (small amounts of
grounds are fine).

For what it's worth, I've switched my home composting
to all worms. However, I keep a relatively large bin
outside at the end of the driveway (a covered bridge
composter - an 'earth machine' works, too), so flies,
schmies, who cares?

I don't really have that many problems. What I do is -

* I cover scraps with 2-3 inches of leaves or paper
(usually leaves - they are free, I don't have to shred
or soak 'em) when I add, and scrape some bedding back
so new scraps are added about 6 in deep.

* I take out the compost scraps fairly regularly, so I
never overload the bin. When I'm starting a new bin,
I'm cautious about adding a lot of feed until I have
enough 'head' of livestock (can you say 'head' of
worms - 'wiggle', maybe?) to eat it. I take excess
scraps to the community garden compost bins/piles,
when  I need to (very rarely).

* I keep my wormies happy, don't let them dry out,
start a new bin when the old one is full, keep lots of
bedding in. This is much easier outside. 

* I tolerate Drosophila predators and competitors in
my bin. Soldier fly larvae are gnarly! Check this out:


http://mypeoplepc.com/members/arbra/bbb/id16.html

I think it isn't just that my wormies are happy - by
having it outside, I can manage the bin much more as a
decomposer mini-ecosystem, with the wormies (E.
foetida, mostly, aka redworms) as the majority
population. Need that diversity, you know... I think
nematodes, fungi and the like make it less a fruitfly
haven.

The observation about temperature is very interesting.
The seasonal cycle is very evident here in the worm
bin, too, and cool temps slow bugs and worms alike
(worms less). Also, I'm observing the same good result
from covering stuff, esp. fruit with a layer of
bedding.

Happy worming,

Don Boekelheide
Charlotte, NC