How To Tell If You’re Over-Fertilizing Houseplants

When I first started growing houseplants and creating my indoor green corner, a friend of mine told me that plants need fertilizer in order to grow healthy and beautiful. Fertilizing plants encourages healthy growth and flowering, but too much fertilizer leads to problems, and potted plants are especially susceptible, because they occupy a much smaller area where fertilizer salts can build rapidly.

It’s well-known that the main ingredients in fertilizers are nitrogen, phosphorus and potassium:

  • Nitrogen encourages foliage growth
  • Phosphorus encourages root growth and flowering
  • Potassium helps plants absorb other nutrients, among other things

To prevent over-fertilizing you need to recognize the symptoms and change the feeding routine. However, you should keep in mind that too much fertilizer can be detrimental to houseplants. Over fertilization can actually decrease growth and leave plants weak and vulnerable to pests and diseases.


Signs Of Over-Fertilizing

  • yellowing and wilting of lower plant leaves
  • browning of leaf margins and tips
  • black, brown or rotting roots
  • slow to no growth
  • sudden death of seedlings
  • leaf drop

Other Signs: The soil in potted plants may also develop a white, crusty surface. Too many fertilizer applications sometimes cause new and unregulated growth, encouraging insect pests and disease.

Besides adding too much fertilizer at once, it’s possible to over-fertilize in less apparent ways, too. Sometimes fertilizer builds up when soil doesn’t drain well. Other times, the fertilizer isn’t flushed through the soil with water, causing root burn. Slow-release fertilizers may help regulate the release of nutrients into the soil over time, but it’s still possible to add too much if you don’t see results as soon as you expect them. All of these activities can cause plants to show signs of over-fertilizing.


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