Burlington-based Gardener’s Supply Company has been sold to its employees. The owner of the 26-year-old garden products retailer started selling shares of the company to its employees in 1987. The company says it could have been sold to outside buyers, but employee ownership reaffirms the company’s commitment to Vermont and its 250 full-time and 100 seasonal employees. The company is privately owned and so doesn’t release sales figures. Owner and founder Will Raap says the founding mission of the company was to spread the joys of gardening.