Tropical patchouli is sensitive to cold temperatures, which makes this plant a prime candidate for growing in a container filled with lightweight potting mix. Choose an 8- to 12-inch-diameter pot with drainage holes that will give the plant room to grow about 1 foot tall and 3 feet wide. Place the potted plant in an area of your home where it will get no more than eight hours of direct sunlight a day. Water the plant when the soil feels dry. Fertilize with fish emulsion every three months per the manufacturer’s directions. Bring container-grown plants inside in autumn and place them in a bright, sunny spot. Move plants outside in early summer when temperatures are regularly above 60°F at night. If you prefer to plant patchouli directly in the garden, dig a hole that roughly matches the size of the pot in which the plant arrives. Place the plant in the hole, cover the roots with soil, then tamp down gently to remove air pockets. Water it thoroughly, then add a layer of mulch around the plant to retain moisture. Allow the topsoil to dry before providing supplemental water. Patchouli can be started from seed. Plant the tiny seeds in a seed-starting tray or container filled with warm soil and place in a bright, warm spot to encourage germination. Use a grow-light if needed. Provide additional heat by placing the tray on a heating mat. Patchouli typically germinates within three weeks. Water patchouli regularly after plants germinate because it is exceptionally sensitive to dry soil. Keep the young plants in a growing environment that includes moderate-to-warm temperatures, moist—but not soggy—soil, and indirect light. Thin the seedlings until only the strongest one is left in each pot. Move plants outside when temps are regularly above 60°F at night. Patchouli blooms in summer, producing white flowers without much fragrance and 4-inch-long leaves when its exacting growing requirements are met. If desired, harvest the larger leaves on dry mornings for use in potpourri or incense. Dry them by spreading them in a single layer on a screen, then setting them in a well-ventilated space where they are protected from direct sunlight. Let the leaves dry completely before crushing them for potpourri or grinding them for incense.