So a little over a year ago (best i remember)
i had a pond in my yard and the plastic liner had broken.
(its about 12ft by 8ft wide 4 or 5ft deep.)
It was a mosquito nursery, and was a big problem.
I finally cleaned it out to a bare dirt floor.
a buddy of mine makes and sells organicfruit juices
and he has 5 gallon buckets of mango, banana, citrus , beet, and other peels.
i dumped about 40 of the 5gal buckets in the hole.
i added 2 large bags of sawdust
about 400lb of coffee groundes
5 or 6 bags of grass clippings
various leaves, yard waste etc...
unfortunately, i have a bad back, and mixing it was a problem.
and.... mistake #1 was putting the peels (very wet, lots of rotting juices) in first.
i did add a few small cardboard boxes at bottom, but, sawdust would have been better
i just didnt have any at the time. i got it a week later.
then i added grounds, grass, leaves, more grounds, cardboard, grounds, sawdust etc...
till it was full.
i put a couple of long 2x6 planks down to walk on it.
and now i finally took them up and tested my weight.
in most areas, it is fairly solid.
in 1 spot i sunk about a foot down.
i dug up a shovel full, and i was surprised to find dirt... ?#@!?>
it was a very dark, very rich "mud"
(it did rain recently, cool temps, and no sun to dry thing out)
it is still about 4 to 6 inches low, so , i am still adding leaves, grounds etc... to it.
it had sunk a little, but , not much.
There are drier spots where the top couple of inches is excellent compost.
but, that very well could be coffee grounds and grass clippings added 6 months ago.
it seems the worms are churning things up also... which must be how i got soil in the mix.
i get 100lb of coffee grounds every week or so from starbucks.
i have used them in experiments of sorts.
also, i can get 7ft tall bags of sawdust from a cabinet maker.
this is like having finely ground wood chips.
i once made a pile of semi-dried grounds, dry oak leaves and semi-dry grass clippings
the oak leaves were small, and the grass clippings had been run-over twice.
this produced the best compost i had ever seen,
i could have sifted it though a pasta colander.
i added a little sand and used it as seed-starting mix (great stuff)
another one was sawdust, grass clippings and grounds.
it made excellent worm food.
and i use it as a mulch... it has to be used as a thin layer and mixed well
as the grounds can form an impenetrable barrier to water.
mixed well, with less % of grounds, can fix the issue also.
i used this mix also to put UNDER cardboard to keep weeds down around fruit trees.
the worms came up and went to town.
the cardboard kept it moist and protected.
i do wish i would have added some coarse sand, as it gets thick and sticky without much air.