Pogostemon patchouli plants are grown for their aromatic leaves, which also have some specialty culinary uses, but are mainly used as incense, perfume and as a natural insect repellent. The dried leaves are packed with linens, which can keep moths at bay and which impart that distinct "hippie shop" scent so familiar to purchasers of cotton bedsheets or pillows imported from India. Whether you are growing patchouli as a commercial crop or a houseplant, harvest it frequently and dry the leaves slowly for the most effective plant growth and patchouli oil preservation.
Cut main stem back to three or four leaf nodes above the base of the plan 60 days after planting patchouli or after the emergence of the first true leaves of seed-grown patchouli.
Inspect the plant carefully beginning 70 days after planting. Cut stems that show one or two yellowing leaves to two or three leaf nodes above the base of the plant. Cut all the appropriate stems for commercial harvest; harvest about a third of the stems at a time to maintain attractive growth for a houseplant.
Spread harvested stems in a single layer on bamboo mats or burlap yardage in a dry, shady location for seven to 10 days. Turn each stem at least once a day.
Pack the stems into burlap sacks or loose-woven pillowcases and hang them with twine in a shady location where they will receive good air circulation for three to four months. Remove stems from the sack and strip the leaves off by running your pinched fingers down the stem. Compost the stems and use the dried leaves as desired.
Repeat the harvesting process every four months. Fertilize the plants with a side dressing of compost or an application of 15-10-10 fertilizer after each harvest.