Analytical determination and confirmation of minimum compost processing times and minimum curing times can aid commercial growers in selecting compost materials that should give them more reliable and consistent results in their operations. Five-cubic-yard volumes of yard-trimmings were assembled into three 1.25-cubic-yard compost piles at 60-day intervals. At the conclusion of the experiment, there were three piles each of compost of the following ages: 10 months, 8 months, 6 months, and 2 months. Compost was collected from each pile and screened through a 0.75-inch screen. Bulk density, water-holding capacity, air-filled porosity, carbon to nitrogen ratio, electrical conductivity, and ATPase activity were determined on samples from each reference compost pile. A bioassay using beans also was performed. These data will be presented.