How To Grow Sage From Herb Seeds: To get a jump start, sow Sage seeds indoors 6 weeks prior to the end of frost season. For areas with a longer growing season, sow Sage herb seeds in well-drained, neutral to alkaline soil in full sun after danger of last frost is over. Performs best in rows 18 inches apart. Thin plants to 12 inches apart when they are 2 inches tall.
For maintenance, prune out the woodiest stems and spent flower stalks each spring. To help the plant to harden off for the winter, stop harvesting early in the fall. After a few years, Sage herb plants become quite woody and less productive. Plan a year ahead to replace them. Replace plants every 3 - 4 years. To help the Sage plant get established, harvest lightly the first year. For harvesting the second year, leave a few stalks in place to allow the plant to rejuvenate.