Hardiness: Protect from frost
Tropical perennial native to Asia. May be grown in the temperate zone in pots, brought indoors for the winter. Plant prefers full to part shade, moist, rich soils, humidity.
The plant thrives under good care but fades fast with neglect–it needs watering almost daily, has zero tolerance for frost and will sunburn if not protected by shade. The seeds are small and are best sown in warm soil, in the light. My favorite method for planting seeds of this sort is to prepare a pot or flat with nice humus potting soil, filling to the lip and leaving the surface rough, not smooth and patted down. Then, sprinkle the seed over the surface of the soil and tamp firmly. This allows the seed to fall down between the roughened particles of soil, and then when you tamp it down with the palm of your hand, the seed is nestled into place on the surface or barely sub-surface. Then, mist with water very carefully so as not to dislodge the seeds, and keep in the light, ever moist, and nice and warm until germination, which takes between one and three weeks. Allow the seedlings to grow closely together at first, and when they attain their second set of true leaves, then individuate them carefully and pot up individually to 4-inch pots. Grow them out that way for awhile, until they fill the pot with roots, and at that point transplant up to gallons. Soon after that, you can make a harvest of the leaves produce a patchouli sachet, or you can extract your own essential oil if you have a distiller. For all practical purposes, under good growing conditions, you can figure 3 months to harvestable years and 1 year to flowers. As I write this, the pervasive fragrance of Patchouli rises up from the packet before me, and I give thanks for this incredible plant, and wish you to have it! Also, in cleaning the flowers to obtain the seeds, the scent of patchouli was almost overwhelming, so this leads me to believe that the essential oil content of the dried flowers may be the highest as compared to any other part of the plant.
Patchouli likes a warm, damp climate in fertile, well-draining soil in an area of full to partial sun exposure. This herb is conducive to container growth, or you can plant it directly into the garden. Patchouli herb plant thrives in a soil pH of between 5.5 and 6.2.
Dig a hole matching the depth of the container in which the herb comes in. Place the plant in the hole and tamp the soil down around the herb to eliminate any air pockets. Give the herb 20 inches of room around it to grow into and water it in thoroughly. Thereafter, allow the topsoil to dry before watering. A good layer of mulch around the patchouli herb plant is recommended to retain moisture.
Patchouli Plant Care
Fertilize the herb each spring with an NPK plant food in the amount of 10-10-10 and thereafter once each month until the fall.
Prune any leaves that are dying, diseased or otherwise damaged. Patchouli is susceptible to infection with leaf blight. Prior to pruning the plant, dip the shears in a mix of 70% denatured alcohol and 30% water to retard the spread of the disease.
Caterpillars love patchouli plants as well, so be vigilant about their discovery and removal.
Winter watering should be reduced to allow the plant to go into dormancy. If you grow patchouli plant in containers, they can be moved indoors for protection, especially in areas with harsh winters. First, acclimate the plant by setting it in a shady area for a few days prior to bringing it inside; this will keep it from becoming shocked by the sudden temperature shift. Place the container in the south facing window where it can then receive at least 6 hours of sunlight.
Harvest patchouli on dry mornings when the essential oils have peaked to get the most benefit from the plant.