Suståne 16-4-8 - Natural Base + Coated Controlled Release Organic Fertilizer Designed for Professional Nursery, Greenhouse, and Landscape Applications - 120 - 150 Day Nutrient Release at 70º F (21º C) Suståne 16-4-8 is perfect for the production of perennials and woody ornamentals. Nursery producers can use Suståne 16-4-8 to grow beautiful Azalea, Holly, Weigelia, Crape Myrtle, Cotoneaster, Boxwood, Spiraea, Salvia, Hibiscus, and Daylily. Suståne 16-4-8 was developed as a combination fertilizer to provide nursery stock with a time-released 4-1-2 nutrient package blended with a 50% Suståne humus-rich, premium natural base. Suståne 16-4-8 Nursery Fertilizer is available in both 180-day and 120-day release profiles to meet the needs of your production cycle. Suståne 16-4-8 Nursery Fertilizer is derived from aerobically composted turkey litter, polymer-coated urea, polymer-coated MAP, and polymer-coated potassium nitrate.