Manure Use in the Garden Horticulture Manure Use in the Garden Manure is the oldest fertilizer known to civilization.
Many gardeners feel manure is superior to synthetic products.
The use of manure however, does present a small risk of food-borne illness from manure contamination. Fortunately the risk of illness can be minimized in several ways. Root crops, such as radishes and carrots, as well as leafy vegetables like lettuce where the edible part touches the soil present the greatest risk for potential problems. Thorough cooking is even more effective because most pathogens cannot survive high temperatures. To further reduce the risk of diseases, manure should be applied at least 60 days before harvesting any vegetables that will be eaten without cooking.