You are doing it wrong. Here’s what fertilizer to use on what houseplants

10. 🍏 Apple Cider Vinegar (Highly Diluted)
Why: Acidifies alkaline soil; ideal for acid-loving plants.
How to Use: Mix 1 teaspoon of apple cider vinegar in 1 gallon of water. Use once every 4–6 weeks during active growth.
Best Used On: Gardenia, Azalea, Calathea, Ferns.
Avoid On: Succulents, Jade, Spider Plant—can make soil too acidic.