Coffee grounds & tea are ok - as long as they have been run through the south end of a worm. Yes, vermicomposting. Red worms & earthworms love both coffee & tea. Once, they have eaten them and pooped them out - they rule. Worm Castings are what they are called. You mix about (
tablespoons to a quart of water, agaitate for about a minute - then let sit over night. It provides very smooth, soluble nitrogen (about .10 percent - not a full percent) but most of all - it provides, beneficial microorganisms like mychorrizzal fungi (which are found in the digestive tract of all red worms & earthworms) these fungi rock... They will turn average plants in the ass kicking, tough as nails, super bud machines. You can buy worm castings on Ebay and make your own Worm Castings Tea (agaitating with a aquarium pump helps) or buy some ready made tea. Blue Mountain Organics makes the best I've ever used.
Don't use straight coffee or tea - both are very acidic - promote (bad) fungi - and attract ants, gnats and other pests of opportunity... Unless, they have been processed by Mr & Mrs. Wiggly Worm.... either compost them or leave them alone...