Plants, like animals, require certain essential minerals for proper growth. In order to maintain an attractive interior garden with high-quality, long lived plants, you must understand and give careful attention to plant nutrition.
A well managed fertilizer program for indoor plants should provide adequate nutrition at all times. An insufficient or excessive amount of fertilizer in the medium is harmful to plants.
Fertilizer is a mixture of minerals applied to the medium to provide essential elements for plant growth. Indoor plants are usually fertilized with a mixture composed of nitrogen, phosphorus and potassium.
The major objective in interior plantscaping is to maintain plants rather than to have them grow: thus the number of new leaves produced should be minimal. Since growth is less indoors, less fertilizer will be needed.
The rate of fertilizer application is related to the light intensity and duration. Plants maintained in high light for long periods require more fertilizer than do those maintained in less than optimal environments.
Plants exposed to natural light require more fertilizer in the period from February to August, as this is the time of year when growth is most active, and little or none after that. More frequent applications at reduced rates, perhaps every two weeks, will maintain more uniform soil nutrition, fostering maintenance of healthier plants.
We at PDI start our fertilizing program in March. We start once in March, full strength. In April we start fertilizing half strength every other week throughout the summer. Fertilize once in September and October to round down our yearly program.