The frequency of fertilizing your houseplants will depend on the type of plant, the type of fertilizer you're using, and the time of year. Generally, houseplants should be fertilized every 2-4 weeks during their active growing season, which is usually spring and summer (May thru October). During the fall and winter months (November thru April), you can suspend fertilization altogether. If you really want to fertilize in the winter, or if you see signs of them actively growing, we recommend you both reduce the concentration of the fertilizer and frequency of use (minimum 8 weeks between fertilizing).
It's important to follow the instructions on your fertilizer package carefully and avoid over-fertilizing, which can lead to damage to the plant. Here are some signs that you may have over-fertilized your houseplants:
Brown tips on the leaves: This is one of the most common signs of over-fertilization. The leaf tips may turn brown and dry out.
Yellowing leaves: Too much fertilizer can cause the leaves to turn yellow and drop off.
Slow growth or stunted growth: If your plant is not growing as quickly as it should, or if it is not growing at all, this could be a sign that you have over-fertilized it.
Wilting: Over-fertilizing can cause the plant to wilt or droop.
Salt buildup: If you notice white or crusty deposits on the surface of the soil, it may be a sign that you have over-fertilized your plant. This can happen when the excess fertilizer salts accumulate in the soil.
Burning: Over-fertilizing can cause the plant to burn or scorch, which can appear as brown or black spots on the leaves.
If you notice any of these signs here are some steps you should take to help correct the problem.
Stop fertilizing: The first thing you should do is stop fertilizing your plants. This will prevent further damage to the plant.
Flush the soil: You can flush the soil with water to help remove excess fertilizer salts. You can do this by slowly pouring water into the pot until it starts to drain out of the bottom. Repeat this process several times until you see clear water draining out of the bottom.
Repot the plant: If the soil is heavily compacted or has a lot of fertilizer buildup, you may need to repot the plant. Remove the plant from its pot, gently loosen the roots, and replant it in fresh soil.
Trim the damaged leaves: If the plant has brown or yellow leaves, you can trim them off with a pair of clean scissors. This will help the plant redirect its energy to healthy growth.
Wait and watch: After taking these steps, it's important to be patient and monitor the plant closely. Don't fertilize it again until you're sure it has fully recovered.
Remember that prevention is always the best approach. Be sure to follow the instructions on your fertilizer carefully and avoid over-fertilizing your plants in the future.