Nursery experiments have shown that sulfur-coated urea was excellent as a slowly available form of nitrogen for ornamental plants in containers. Best plant growth resulted when the sulfur-coated urea was incorporated in the potting mix and the plants received fertilizer applications during the growing season. Even without additional fertilization, the controlled-release urea was able to supply adequate amounts of nitrogen for several months' growth. Excessively heavy applications resulted in plant injury and death.

The fertilizers for these experiments were supplied by the Tennessee Valley Authority, Division of Chemical Development, Muscle Shoals, Alabama. The experiments reported were conducted at the Ponto Nursery, Inc., Vista, and the John E. Edwards Nursery, East Palo Alto, California.