Leftover tea does not provide a balanced feeding plan. Separate compostable leaves from routine watering and check the root zone before trying a kitchen-based remedy.
Tea is not a balanced fertilizer
Tea strength, ingredients and storage vary. The liquid does not supply a measured nutrient plan, and a pile of leaves in a pot is not the same as finished compost. Sweetened or milk-containing leftovers add further residues.
Keep the root surface accessible
Do not bury fresh tea scraps around indoor roots as an automatic improvement. A dense surface layer can make watering and inspection less straightforward. Watch the growing medium itself rather than judging a plant by the amount of household waste added.
Choose an appropriate route
Suitable plain plant material can go through managed composting. Use suitable water for routine care and a labeled feed where necessary. If growth is weak, identify the plant and check light, roots and drainage before assuming a lack of potassium or another specific nutrient.
Related reading: Overnight Tea and Plants: Storage Is Not Composting.