Patchouli oil can be used by itself to create a distinctive fragrance or mixed with other essential oils like sandalwood to create a signature organic scent. Some even add it to cosmetics. But patchouli is much more than perfume--its antibacterial properties make it an effective deodorant; it can be used as an insect repellent and even an effective breath freshener that effectively masks the smell of alcohol.
Wait until the right time to harvest. Timing is one of the most important factors when harvesting patchouli for oil. Roughly five months after patchouli has been transplanted, the bottom leaves on mature branches turn a lighter green or brown color and the plant begins to emit its characteristic fragrance. This is the patchouli plant's way of letting the gardener know that the oil is ready to be harvested. Harvest too early and you will get a much smaller yield of inferior-quality oil. Harvest too late and the patchouli plant won't grow back as successfully.
Sharpen your pruning shears and disinfect them with a 10 percent alcohol solution. This will prevent you from spreading disease and leave behind a clean cut, which will help protect the plant from insect or fungal infestation.
Harvest the patchouli early in the morning or late in the afternoon when the sun is weak. Use sharp pruning shears to cut the the top 16 to 24 inches of each mature branch--those with six to seven leaves of which the bottom few have yellowed or browned. Leave four to six buds near the base of the plant so that it will grow back quickly.
Harvest at three- to four-month intervals throughout the growing season as other branches grow and mature. A crop of patchouli will last for around three years, but the first two to three harvests provide the best oil.
Spread the patchouli leaves to dry in a shady place for seven to 10 days. Turn them once daily.
Store the dried leaves in a gunny bag, suspended off the ground, for three months before you extract the oil.