Native to the tropical Americas, datura (Datura spp.) are commonly called “Angel's Trumpet.” Their fragrant, most often white, trumpet-shaped flowers open in the evening, perfuming the air with their sweet, heady scent. They produce a spiked, rather large seed pod, the description of which gives the plant its other common name: thornapple.
Fill 2-inch pots with indoor potting soil. Sow several datura seeds in the center of each pot by making a slight indentation in the soil with your finger and tapping the seeds into the hole. Cover with an additional sprinkling of potting soil and lightly firm the top of the soil.
Water newly planted seeds from the bottom. Place the small 2-inch pots into a larger pan and add enough water to come halfway up the sides of the 2-inch pots. Allow them to sit until the surface of the soil looks moist. Add more water if the small pots absorb all the water in the pan and their surface soil does not yet look damp. Remove the pots from the pan and allow excess water to drain away.
Put the individual pots in a warm spot at temperatures of approximately 65 to 68 degrees Fahrenheit until the seeds germinate, which will take 14 to 28 days. The top of the refrigerator or on a seed-starting mat are good places to keep the pots until the seeds germinate. Water pots as needed to keep the soil moist, using the method in Step 2.
Move the individual pots under artificial lights as soon as the seeds germinate. Put them approximately 4 to 6 inches below the lights and provide a way to raise the level of the lights as the seedlings grow taller. Keep the lights on the plants 12 to 16 hours a day.
Thin the seedlings to the strongest one in each pot when they are 2 to 3 inches high. Use a small pointed scissors and snip off the unwanted ones so as not to disturb the roots of the selected plant.
Harden off seedlings beginning about one prior to the average date of your last spring frost. When temperatures are above 50 degrees Fahrenheit, put the pots outdoors in shade, starting with a couple of hours a day and gradually increasing their time outdoors over a period of a few days until they are outdoors all day. Then condition them to full sun exposure using the same method over several days. Bring them indoors at night or if frost threatens. Plant them in your garden when they are spending all of their time outdoors and all danger of frost has past.