Corms are lumped together with bulbs much of the time. They differ from bulbs in that they don't have the storage rings that bulbs do. Instead, they are a swollen section of the stem base that stores the nutrients for the flowers to bloom. Like bulbs, corms often are classified as spring or summer blooming. Hyacinth are an example of spring bulb and gladiolas are summer bloomers. Plant spring corms in fall for early spring flowers and summer corms after all danger of frost has passed in spring.
Prepare a well drained garden bed in full sun prior to planting. Lay a 3 inch layer of mature compost over the bed and till it in to an 8 inch depth in order to aid drainage and soil nutrition.
Apply a phosphorus-rich bulb fertilizer to the bed prior to planting. Follow manufacturer's instructions for application amount as this differs by brand.
Sow corms 3 inches deep and 3 inches apart. Plant in the hole so the pointed end of the corm is facing up and the roots are facing down.
Water the beds thoroughly after planting. Cover spring corms with a 3 inch layer of organic mulch to preserve soil moisture and temperature over winter. Mulch over summer corms if desired for appearance and moisture retention.
Fertilize spring corms with a complete fertilizer in early spring before they begin flowering. Fertilize summer corms with a complete fertilizer every 6 weeks during the growing season.
Keep soil moist but not soggy. Water as needed when the soil begins to dry out.