Impatiens, one of the most popular annual flowers in the United States, add color and beauty to partially shaded areas of the garden where other plants may fail to bloom. Gardeners commonly use the plants for shady borders and massing under trees. Impatiens bloom in early summer through fall, producing abundant blossoms in a wide range of colors, including red, pink, white, orange and violet. Typically grown from seed, impatiens require little care once established. The plants often naturalize if provided with proper care and reappear each year without the need for restarting from seed.
Start impatiens flowers indoors about 10 weeks prior to the last frost in your area. Fill cell packs with a high-quality seed-starting mixture, and sow each individual seed in a separate cell. Do not cover with soil, as light is required for germination. Instead, place the seed on top of the soil and tamp down with your fingers.
Place the cell pack in a warm area of the home that receives indirect sunlight. Do not expose the seedlings to full sun. Water the plants once every five to seven days throughout the 10 weeks. Germination occurs in 14 to 21 days.
Plant the impatiens during spring, as soon as the risk of freezing has passed. Choose a shady planting site that receives about 2 to 4 hours of filtered sunlight throughout the day and consists of moist, well-drained soil.
Fertilize the soil prior to planting, using a slow-release fertilizer to release nutrients into the soil throughout the growing season. Check the dosage and application instructions provided by the manufacturer for the best results.
Dig a hole in the soil slightly larger than the roots of the impatiens seedlings. Insert each plant into a hole, and gently cover with soil. Water lightly to collapse any air pockets and initiate new growth. Space impatiens 12 to 18 inches apart.
Water impatiens once a week during periods of dry weather only. Soak the soil thoroughly to ensure that the roots receive plenty of moisture. Do not water during weeks that receive more than 1 inch of rainfall.
Pinch back impatiens by 3 to 4 inches if they begin to grow too tall, and the plants will begin to grow in a more compact, bushier habit. Remove all damaged or diseased foliage whenever possible to increase the plant's overall health.