Using sheep manure as fertilizer for the garden is not a new idea. People have been using animal manures as a very effective organic material in gardens for a long time. Sheep manure, like other animal manures, is a natural slow-release fertilizer. Nutrients in sheep manure fertilizer provide adequate nourishment for a garden. It is high in both phosphorus and potassium, essential elements for optimal plant growth. These nutrients help plants to establish strong roots, defend against pests, and grow into vibrant and productive plants.