The Nutritional Needs of Corn Plant Houseplants

Fertilizer Elements

• Fertilizers contain nitrogen, phosphorus and potassium. These three main elements are detailed on the fertilizer label as the N-P-K ratio. They supply the soil nutrients the corn plant needs to grow well and produce its healthy foliage. Fertilizers also contain trace elements that may not appear in the main ratio, but are instead listed on the back of the label. These include zinc, magnesium and other trace minerals that help the plant grow well but aren't as vital to the corn plant's health.

Fertilizer Type

• Indoor corn plants typically grow in containers with a limited soil volume, necessitating regular watering. Each time you water, you wash some of the nutrients out of the soil. A corn plant houseplant requires more frequent fertilization than those grown outdoors to make up for the nutrient loss caused by irrigation. A soluble, or liquid, fertilizer becomes available to the plant roots more quickly than a granular type, so it's preferred for feeding indoor corn plants. Use a 20-20-20 fertilizer ratio. Corn plants do not flower, so they do not need the higher amounts of phosphorus found in indoor flowering plant food. Instead, they need equal amounts of the three main nutrient elements to encourage healthy and lush foliage and root growth.

Application

• Corn plants remain green year-round when grown as houseplants, but they put on active new growth in the spring and summer. They go into a semidormant state in the fall and winter. During semidormancy, the corn plants don't require fertilization, since they put on little growth and supply their own nutrient needs from their root stores. Supply nutrients through once-monthly fertilization only during the spring and summer, and then stop fertilizer applications during the dormant periods. Dilute the fertilizer in water according to the rate on the fertilizer package for the size of your corn plant's pot. Application amounts can differ between fertilizer brands.

Concerns

• Water also contains trace elements, and is a vital part of the fertilization process, since the nutrient solution is diluted in water. Home tap water often contains fluoride, which is detrimental to corn plants. Use distilled water for mixing the fertilizer solution and for regular watering. Alternatively, set out a pitcher of tap water, uncovered, for 24 to 48 hours before using it on the plant. This allows the fluoride to evaporate out of the water so it doesn't harm the corn plant. Avoid superphosphate fertilizer blends, which have additional phosphate in them, as these also have fluoride in the formula.