Sweetfern thrives in well-drained, sandy or rocky soil with full sun to partial shade. Plant in early spring or fall. Space plants 3-4 feet apart to allow for spreading. Water regularly during the first growing season to establish roots, then reduce frequency as the plant is drought-tolerant. Prune in late winter or early spring to maintain shape and encourage new growth. Sweetfern is a nitrogen-fixing plant, so it requires minimal fertilization.