As I drink quite some tea, I often wondered what to do with the remaining leaves. Googling around, I found that I could use them to fertilize plants. But from different sources, one even suggesting to let the leaves ferment in water for a couple of weeks before using the water. That leave me to some related questions:
can I simply lay the used leaves at the bottom of plants? Or should it be dried, or fermented?
is it good for both house plants and outside plants?
does green or black tea makes a difference?
I think that those questions are related enough to be combined.
On bedded plants, this won't hurt anything, In potted plants, there is a possibility of altering the pH levels, especially if fermented. Also, the decomposition process could sour the potting mix. And the nutrients gained will be very minimal (minuscule compared with a balanced extended release) Basically whether indoors or outdoors, if you don't have a compost heap, I would use the leaves very lightly for potted plants (indoor or outdoor), or more freely in soil, in a bed.
Without a compost heap, you won't be able to use up all your tea leaves - putting them on the compost is the best way to use them. However, what you can do for acid loving plants is repot them, using some of your used tea leaves (of whatever type) mixed into the potting mix. They don't have to be dried to do this, but make sure you mix them through the potting medium well so they're not in clumps. Or water the plants with tea - if your leaves are mixed with water, the resulting tea won't be as acidic as the leaves themselves.
In practice, of course, the amount of tea leaves you can use in this way will be small in comparison with the amount you use each day for drinking yourself.
Tea is quite amazing, my grandmother alsways discharged the contents of her teapot onto her garden just by the back door.
Everything seemed to thrive especially the lilies which were an annual wonder.They came up asking for two lumps please.
We use mostly tea bags these days which do end up in the worm infested compost bin but the regal pelargonium on the window sill does get a drink of the rinsed out tea cups at watering time and requires no other feeding so maybe you can do just that to your pot plants and gain some benefit from your tea.