Indoor Plant Fertilizer


All plants depend on soil for nutrients to grow and flourish. Without proper indoor plant fertilizer, plants are susceptible to diseases, wilting or even death. The right fertilizer will ensure the precise variety and amount of nutrients needed for quality soil.


The function of indoor plant fertilizer is to add nutrients to potted soil. The amount of nutrients for plant growth depends on the size of the container, lthe ight requirements of the plant and the plant's growth rate. Plants in low light and with a slow growth rate require much less indoor fertilizer than their faster growing high-light counterparts.


Indoor fertilizer is available in a variety of forms. Concentrated liquid types require mixing with water to acheive the proper concentration. Time-released granules mix with the original potting soil to release fertilizer over an extended period. Stakes dissolve slowly and release fertilizer into the soil with each watering. Indoor fertilizers usually have a nitrogen-phosphorous-potassium ratio of about 20-20-20.

Time Frame

The best time of year to use indoor fertilizer is during the growing period. Most houseplants grow during early spring months through the early fall months. Monthly fertilization provides additional nutrients for plants during this time frame. During the fall and winter months, many houseplants need little to no indoor fertilization to sustain growth and thrive. Avoid fertilizing dry soil, advises N.C. State University.


Over-fertilization is a common problem with indoor fertilizer misuse. Plants suffer reduced growth, brown or wilting leaves, decreased bloom yields and falling leaves with over-fertilization. If a white crust appears on the soil surface, this is an indication of excessive fertilization leading to the formation of salt deposits. Salts can also accumulate from watering with hard water. A high concentration of salts in the soil makes it hard for roots to absorb water.

Leaching Soil

Leaching soil is the process of removing impurities and unused indoor plant fertilizer. Approximately every four to six months, drench each houseplant and allow it to drain thoroughly. Allow the plant to drain and rest for roughly an hour, and repeat the process to leach the soil.


A common misconception is that frequent and heavy indoor fertilization encourages stronger and healthier plant growth. In fact, stunting of growth can result, and plants can die from too much fertilization. Avoid weekly fertilization and refrain from using the schedule listed on indoor plant fertilizer labels, warns N.C. State University.

Keywords: indoor plant fertilizer, fertilizing house plants, indoor plant care

About this Author

Daniel Smith graduated from technical school in 1993 and has been writing since 2005. His has written numerous articles for the instructional website called eHow in areas including gardening, home improvement, celebrating special events and health-related topics.