Types of fertilizer
When it comes to feeding your houseplants, there are two types of fertilizers: organic and synthetic. Organic fertilizers include composted manure, fish emulsion and other natural substances containing nitrogen, phosphorus and potassium. These nutrients help feed the soil in which your plants grow, but they can also be used as foliar sprays for indoor plants. Synthetic fertilizers contain chemicals that mimic the nutrients found in organic matter and are often more concentrated than organic products.
Most houseplants should be fertilized every two weeks during their active growing season (spring through fall). When you feed your houseplants at this frequency, you’ll need to use a balanced fertilizer (containing nitrogen, phosphorus and potassium) that’s specifically formulated for houseplants. If you use any type of synthetic fertilizer on your houseplants outside their active growing season (winter), it can cause leaf burn or yellowing of the leaves and may even kill them!