Pot corn plants in a growing mixture comprised of 2 parts loam, 1 part coir and 1 part coarse sand. Fill the pot only until the soil is flush with the bottom of the plant's thick, fibrous canes. Shake the pot to settle the soil and add more, if necessary.
Position corn plants where they will receive moderate to bright light, such as within 3 to 6 feet of a sunny, south-facing window or within 1 to 3 feet of a shaded window. Try to provide as much light as possible while restricting direct sun exposure so that the plant won't drop its leaves or lose its coloring.
Water corn plants only when their soil has dried out completely. Drizzle water onto the soil around the base of the canes until the soil feels lightly to moderately moist at a depth of 4 inches. Water deeply but infrequently to keep the plant from developing root rot.
Feed corn plants once a month from early April until September using a diluted 10-10-10 ratio fertilizer. Apply the fertilizer according to the manufacturer's recommendations, but use only a quarter of the recommended amount. Water the soil deeply after feeding.
Repot corn plants into larger containers only when they are dangerously top heavy in their old planter or they show signs of restricted growth such as stunted new leaves. Choose a planter measuring 1 to 2 inches larger than the old container and use the soil mixture described in Step 1.