Growing Plants Indoors Nutrients. Most of the nutrients that a plant needs are dissolved in water and then taken up by the plant through its roots. Fertilizers will help to keep the soil supplied with nutrients a plant needs. Don't apply too much too often. Fertilizer won't solve all of your plant problems, so make sure your plants have good light, good soil, and good drainage. The three most important nutrients are nitrogen, phosphorous, and potassium. Nitrogen is used for above ground growth. This is what gives plants a dark green color. Phosphorous helps plant cell division. It aids in flower and seed production and in the development of a strong root system. Potassium helps fight off disease and provides for strong stems.

Room to Grow Temperature Light Water Air Nutrients What's Next?