How to fertilize indoor plants?
Plants need balanced fertilizer to grow well
House plants need nutrients and fertilizers from potting soils in order to survive, if you don’t re-pot plant, or add nutrients to the soil, plant will eventually die. Fill your pot with a balanced 10-10-10 (NPK) fertilizer as most houseplants thrive with balanced 10-10-10 fertilizer. NPK is short form for nitrogen, phosphorus and potassium.
If you have a flowering plant, you can buy a fertilizer that is high in potassium.
If you have a foliage plant, you should get a fertilizer or potting soil high in Nitrogen.
Plants also require micronutrients that need to be replenished by adding potting soil or fertilizer in order to survive.
Cacti or succulents require a special potting mix specifically designed to drain water efficiently. They also need pots with plenty of holes on the bottom. These prevent too much moisture from being held in the soil, which can kill the plants.