Some plants, notably ferns, do best when the soil is kept evenly moist. For other plants, such as cacti and succulents, the soil should dry thoroughly between waterings. In this case, move plants farther from the glass or filter light with a sheer curtain. He says people have a tendency to overfertilize plants. But too much fertilizer does more harm than good.
Fertilizer primarily promotes growth.
Use a fertilizer labeled for houseplants, and apply it at half strength, suggests Gardner. As a guideline, fertilize regularly in spring and summer, when plants are actively growing and can make most use of the added nutrients. Cut back in fall, when growth slows, and stop fertilizing once daylight-savings time ends. And, to prevent root burn, make sure to always moisten the soil before adding fertilizer. Dusting leaves does more than show off plants.