Impatiens grow in damp, rich soil, and full-sun to partial-shade. The flowers bloom in the late summer and early fall. The seed-pods that form in the fall burst open when touched or disturbed, scattering the seeds. Annual varieties of impatiens self-seed in the fall and return each spring. In warmer climates, perennial varieties will flower all year. The bright, colorful flowers attract bees and other beneficial pollinators to the garden all summer.
Fill a seed-starting flat with compost or seed-starting soil mix. Smooth out the soil and add water until it is evenly damp. Press the top of the soil down with the flat of your hand to firm the surface; press gently to avoid compacting the soil.
Scatter impatiens seeds over the surface of the seed-starting flat and cover with a 1/8-inch dusting of soil. Place the seeds in a greenhouse or on a windowsill to germinate. Keep the soil damp with frequent, light waterings.
Transplant the seedlings into individual containers when they are 1 to 2 inches tall. Prick the seedlings out of the seed-starting flat by gently lifting sections of the seedlings out of the tray and separating the individual plants. Use your fingers to gently tease the young plants apart being careful not to damage the delicate roots or stems.
Fill individual 2-inch pots or a flat of 2-inch cells with compost. Make a hole in the center of each cell or pot and place the roots of one seedling into the soil. Cover the roots with soil and press down around the stem with your fingertips.
Water the impatiens seedlings daily or every other day to keep the soil damp, keep them in a greenhouse or windowsill where they will get filtered, bright light. Avoid hot windowsills when the sun is shining though the glass.
Transplant the impatient seedlings outside in the late spring or early summer when the air temperature is consistently above 65 degrees F. Dig a 3-inch wide, 2-inch deep hole for each seedling. Slide the seedlings out of the pots or cells and place one in each hole, making sure that the seedlings are buried as deep as they were in the pots. Water the area until the roots and soil is damp all around the new transplants.