wrote in message
ups.com...
How about it? Just dug a bed and thought I'd load it
with coffee grounds. The lawn too. Been saving them
for years. How much is over doing it? Dan

Dan, who the heck knows. I have not seen any analysis that says how much is
too much. Here are a few top of the head considerations however. I am
talking here about used coffee grounds.

Some reference I read a while back on the net said they had an NPK content
of 3-1-2 (although various claims differ this seems around the most often
quoted). This is about the same as pelletised organic poop based lawn
fertilisers (chicken or sheep) although the poop fertilisers may have a
slightly higher phosphate mix. I have made a big batch of compost using alot
of grounds and it heated up quickly which suggests there was a good amount
of nitrogen available.

If it is 3-1-2 then I suggest you apply it much the same as any other
fertiliser with that same mix. That is, if a pelletised poop fertiliser with
that npk mix says spread so much by weight across so much a square metre of
grass do the same for the coffee grounds. IfIt also may depend what you are
trying to put in to your soil. Blood and bone has a NP (no K) mix of about
6:6 or there abouts. If you want the same addition of N from coffee grounds
you would need about twice the amount as B&B. If you want the same amount of
P that B&B has you would need about 6 times the amount of coffee grounds.
For the lawn best dry the grounds, that way they will not lump together.

Similar to you I have just built a raised garden and thrown some coffee
grounds on it as a fertiliser/soil conditioner. The bed will be lying fallow
for some time so I am not too worried about whether I added too much or too
little. Weathering and worms will take care of a lot of that. If I was close
to planting I would be a little more careful and treat it like any other
fertiliser. I know roughly what my soil ph is so maybe I will test it closer
to planting to see if there has been any change in ph.

I also use the grounds as a mulch. Some directly to beds and other times
mixed in with wood mulches to add some nitrogen in to the soil. The mulch is
only about 2-3 cm deep at most so it is not super heavy and I have not
noticed any adverse reaction so far in the planys. The wood mulches are
there to keep down weeds so I am not too worried about whether I have gotten
the coffee grounds in exactly the right proportion.

So, if in doubt I guess use as a benchmark against other types of
fertilisers. If applying to a bed that may be fallow for some time it should
not be a big issue. If using as a mulch maybe mix it with other things like
sawdust or dried leaves.

There are different claims that coffee grounds are acidic (see below), if
you subscribe to that theory you may want to use it sparingly. Maybe you may
like to do a ph test. Maybe that is something I should do as well.

http://www.ibiblio.org/london/permac.../msg00090.html
An old Rodale book - Complete Book of Composting gives the
following:

coffee grounds,
fresh - Moisture - 62.9%, Ash .5%, N 1.84%, P2O5 .03%, K2O .12%
composted 58% -- 1.65% .22% 3.0%

As always, adding high levels of uncomposted (fresh) organic matter can
"distract" the microorganisms normally relied upon for making N available to
the
vege crops. Usually, N needs to be added to make up for the temporary
shortage.
Same is true for "green" sawdust, leaves, etc.

If adding N isn't desirable, sounds as if the person might be better off
composting the material. If there's enough garden area available the person
could sheet compost in an area not to be planted this year. Otherwise I'm
guessing that a regular compost pile, with plans to use for late season
crops or
for plants next year, might be better.