Asiatic lilies are flowers that grow from hardy, fleshy bulbs that never go completely dormant. These lilies are quite easy to grow and require limited care and attention. Asiatic lilies are sun lovers that grow into generous clusters when healthy and come in a wide array of colors and forms.
Plant your lily bulbs in the early spring or late fall, just before the ground freezes. Make sure that the planting location allows for a full day of direct sunlight. The area should also be well irrigated to prevent your lilies from resting in standing water, which will rot or kill the lilies. The growing area must provide ample room for the lilies to spread. Plant your Asiatic lilies at least 12 inches apart and with the bulbs at least 3 to 5 inches in the ground.
Fertilize your Asiatic lilies with a slow-release phosphorous fertilizer once each year. The fertilizer application should be applied in the early spring, after the last frost of the season. Asiatic lilies do not require more than one application each year, as their bulbs are susceptible to fertilizer burn. The ideal phosphorous fertilizer formula is 5-10-10. Apply the fertilizer around the lilies’ patch and ensure that the fertilizer does not directly touch the lilies themselves.
Water your Asiatic lilies regularly. While your lilies may require daily watering during the hot summer periods, you may only need to water your lilies two or three times per week during more moderate temperatures. Your watering schedule should be dependent upon your climate, temperatures, and growing location. Water your lilies in the early morning and apply the water around the base of the lily. Avoid watering in the late day and never over-water. This will promote the development of botrytis blight, which attacks the leaves of the lilies, causing spots and browning.
Prune away dead and wilting flowers by snapping them off of the stem. Avoid cutting or pruning Asiatic stems until the final cut of the fall. Once winter’s first frost occurs, trim back the flowers, stems and leaves of the lily. Cover the Asiatic lily patches with mulch for the winter to protect the bulbs from frost. If the lilies become clustered, dig up the bulbs, divide them and replant them in the patch. Split the bulbs carefully with a sharp knife, ensuring that you do not damage the root base. Clustering of lilies will cause stunted growth and fewer blooms. Thinning the bulbs will promote more vigorous growth and greater blooms. The bulbs must be replanted immediately to avoid drying and damage.