coffee and tea for plants?

[destinydai.livejournal.com]

i think i read somewhere recently how people "recycle" their tea bags by putting them into the soil, either broken out of the bag, or still in the bag ... and i half-way recall something about tannins - and how those are supposed to be good for the soil?

just a few questions - does this also apply to coffee? both left over liquid and used beans?

is there a "too much" level? i have a lot of plants in the window sills, and quite a few outside that could use a natural fertilizer/mulch ... and we drink plenty of both tea and coffee ... but i dont' want to kill any of my plants!

++cross-posted to quite a few places! thanks for your help!++