Greenhill Worm Farm

Greenhill Worm Farm is a vermicomposting business located in the Greenhill community of Rutherford County, North Carolina. The farm is a carefully managed, hands-on operation that started as a backyard hobby and soon grew into a business. Greenhill Worm Farm raises composting worms and sells worm castings and worm casting tea, powerful soil amendments that supercharge soil. 

The business is owned and operated by Sallie Smith, a former middle school math teacher. Sallie spent 30 years teaching in the Rutherford County School system. When she isn’t wrangling worms, Sallie can be found enjoying time with her two grandkids, volunteering at the Ruff’ton Roots Community Garden, roofing with the Women Roofers of Rutherford County, or serving on the Board of Directors at the KidSenses Childrens’ Museum in Rutherfordton.

Sallie focuses on creating the highest quality worm castings (also known as vermicast) for farmers and gardeners in Western North Carolina. Her mission is using worm castings to help growers build naturally fertile, living soil. Sallie believes in feeding the soil not the plant, a practice that ensures sustainable growth and productivity without the use of synthetic fertilizers or chemicals.

Greenhill Worm Farm raises Red Wigglers. The worms are housed in hand-built continuous flow-through bins and in carefully monitored breeder bins. Material is screened through a motorized trommel where an eighth-inch screen separates the castings from the worms. Worms are returned to the bins to continue their work, while castings are stored in a temperature and moisture-controlled setting.

Timing is key to producing quality castings. That’s why Greenhill Worm Farm castings are given several months to finish before screening begins. Castings that are harvested too soon lack the level of beneficial microorganisms present in high quality worm castings. From start to finish, Greenhill Worm Farm casting production takes anywhere from 3 to 4 months. 

Feeding thousands of worms keeps Sallie busy. Worm food includes bedding, manure, and food scraps. Bedding is a mix of manure, leaf mold, wood chips and shredded cardboard. Manure is locally sourced from an organic, herbicide-free farm. Food scraps are donated by local food pantries, farms, and produce stands which not only feeds the worms, but also helps divert food waste from our landfills. 

Greenhill Worm Farm castings go through a rigorous quality control process. Composite samples are taken from each batch of castings and sent to the compost testing lab at North Carolina State University. If target values for pH, C:N ratio and other important factors are not met, that batch of vermicast does not go to market.

Worm castings are useful for home gardeners and farmers alike. Castings can be used on vegetables, herbs, ornamentals, perennials, annuals, indoor plants, shrubs, trees and even lawns. Castings can be applied when transplanting, used as part of a soil mix or worked into an entire garden bed. Castings make an excellent addition to container plants, raised beds or seed starting mixtures. Castings can also be made into a compost tea and applied as a liquid.

Worm castings are the only soil amendment that has passed through the body of an earthworm. This unique feature provides a host of benefits found only in nature. Soils amended with worm castings show improved moisture retention, earlier and more successful germination rates, better structure, more organic matter, and increased microbial life. Worm castings also make nutrients more easily accessible to plants. As a result, plants are healthier and more vigorous with increased root structure, greater yield, and heightened productivity.

Greenhill Worm Farm’s vermicast is an excellent addition to any grower’s soil fertility plan. Greenhill Worm Farm castings are used by several of our vendors to help nourish and replenish their soil including Subtle Seed Hemp Farm and Deer Valley Farm. They are also part of Lindy Abrams’ soil fertility strategy at Ruff’ton Roots Community Garden.

To order worm castings, contact Sallie at or text 828-429-9162.