Simply attach the feeder to the garden hose, insert the refill bottle into the feeder and then spray plants and flowers. One refill bottle will feed 400 sq. ft. in approximately 15 minutes. For best results use every 7-14 days. Ideal for all types of flowers, vegetables, trees, shrubs and lawns. No mixing, no measuring, no mess. No more guessing when the plant food is gone — when the bottle empties, feeding is done. Automatically applies plant food evenly. This is a starter-kit with 2 plant food refill bottles.