Fertilizer is necessary to help both indoor and outdoor plants grow. Fertilizing outdoor plants every two weeks during their growth season is the ideal recommendation. Moderation is the key to fertilizing your houseplants. Do not necessarily go by the guidelines of the manufacturer's label, as many factors can influence how much fertilizer your plants need.

Frequency of Fertilizing

Plants need light as food. Indoor plants do not get as much light as they would outdoors, which is the reason to add food or fertilizer. Potted houseplants deplete the micronutrients in their soil and those have to be replenished. Light fertilizing is recommended up to twice a year during your plant's growing season., from March to October. All plants need to be fertilized as they show new leaves or stem growth. The type of plant, the amount of light it is getting, and how frequently you are watering it will determine how much you need to fertilize. The rule of thumb is to wait a month if you just purchased the plant or if it was just repotted. Never fertilize a weak plant. Plants use fertilizer best during their intense growing phases, usually spring and summer. Reduce the rate of fertilizer by a quarter in autumn. In winter, do not give your plants fertilizer. If the plant is dormant, do not give it fertilizer. Root damaged plants or insect infected plants should not get fertilizer. For indoor African violets, bi-monthly feedings of 1/4 teaspoon per quart of water works best. Add fertilizer when the soil is moist so that the roots are not harmed.

Signs that your plant needs fertilizer

Dropped leaves, small or no flowers, weak stems, pale leaves and weak new growth are clues that your plant needs to be fertilized. Signs of over fertilizing are wilting leaves, white crust on the soil surface, oddly shaped leaves, brown spots or edges that look scorched. Plants do not absorb large quantities of fertilizer.

Choosing the right fertilizer

Each type of plant has specific fertilizer needs. Nitrogen, phosphorus and potassium are the major ingredients in fertilizers for houseplants. For flowering plants, you want a fertilizer with less nitrogen. Houseplants generally like the balance of 10-10-10 fertilizer meaning the same amount of nitrogen, phosphorus and potassium.

Source:

Dummies

Guide to houseplants

Mahalo