I generate more tea leaves than coffee grinds, so I googled tea leaves as fertilizer. Two websites claim that tea leaves are the best thing since sliced bread (to use a US metaphor), and that they kill fungi, kill weeds, improve water retention, etc.
I find it hard to believe that tea leaves will attack weeds but not attack the trees.
Yes you can use it as fertilizer, as a part of your regular scheme like coffee grind will do. It can not replace your regular fertilizer.
You can use it liquid or chopped and will kind of have a disinfectant effect due to "tein" , the working ingredient.
just found this on a website;
According to a study by the University of Florida, tea waste contains 4.15% nitrogen. That's about twice as much nitrogen as in coffee grounds. Tea leaves also contain almost twice as much phosphorus and potassium. The study found that tea leaves have an NPK of 4.15/0.62/0.4, while coffee grounds have an NPK of 2.08/0.32/0.28.
Weather or not fertilizer in tea leafs are awailable to your tree or not is depending on your soils ability to break down, mineralize and contain them. Most bonsai mixes containes a high percentage of dead nonorganic materials that do not have this ability.
I knew about coffee grinds. Did not know about tea leaves. It is not my thing. There is so much good fertilizer out there that I just toss my green scaps on the compost, and put it well-compsted, in the soil of my garden