Impatiens are an annual flower that comes in a large variety of colors, including pink, blue, yellow, red, white and purple. Old-fashioned types are fairly tall, up to two feet, but the more common modern impatiens available are as short as six inches from the ground and more compact, spanning 10 or 12 inches around. They are liked by many gardeners for their shade tolerance. For the best coloring of impatiens flowers, they need filtered light or partial shade, as direct or full sun will fade the blooms. They prefer neutral to slightly alkaline soil, with a pH around 6.0 to 6.5.
Impatiens grow well from seed, but are slow to germinate. Plant seeds in a sterile, soilless potting mix or in seed flats. Start impatiens seeds well in advance of spring; you can plant seeds indoors 6 to 10 weeks before setting the seedlings outside. They can be hardened off and set outside after the last chance of frost damage. If you start with impatiens seedlings forma nursery or garden store instead, plant after frost danger is past, and choose a partially shaded location with good soil. If you have the tall varieties, space them 18 to 24 inches apart, while the smaller, compact impatiens can be planted from 8 to 10 inches apart.
Caring for Impatiens
Take note of the location of your impatiens when determining care guidelines. They are favored for under trees and large shrubs, as they need shade, but in such a location, they will need more water and fertilizer, as they will be competing for nutrients with the tree roots. Impatiens needs rich, moist soil, and it’s often a good idea to mulch them really lightly in a layer around the bases, to keep water near the roots longer. Impatiens will let you know when they need water, as the soft stems wilt very quickly when they are without water for too long. Using a liquid fertilizer once a month will help keep impatiens blooming and growing lushly all summer. Impatiens is an annual, and must be replanted each year, but usually does not need pinching or pruning through the growing season, so most of your work for impatiens will come at planting time. If you find your impatiens begins to get too tall and spindly, cutting it back will renew the plant’s efforts toward blooming, and reduce the top-heavy growth. Whether or not to prune is up to you, however, as it’s not needed for the health of the plant.
Pests & Diseases of Impatiens
Most pests and diseases that affect impatiens can be avoided with proper cultivation and care. Moisture stress is a common problem for impatiens across climates; without enough watering, they will not only wilt, but if the wilt is allowed to continue, they will drop leaves and flowers and be much more prone to pests and diseases. In the germination phase, impatiens is prone to damping off, so plant plenty of extra seeds in case this happens. Some plant viruses affect impatiens, but these are difficult to prevent or fight, beyond ensuring you buy seeds, seedlings and plants from reputable nurseries, and keeping your garden tools and containers scrupulously clean. Fungi, rots, and blights also can affect impatiens. Keep soil moist, but not soggy or squishy, to avoid these, and if you see any spots, rot or blight symptoms, remove and discard the dead, dying or diseased parts of the plant to keep it form spreading. Insects to watch for include spider mites, aphids, mealy bugs, and thrips; wash eggs and larvae off plant stems if you find them, and keep mulch clean, dry and light.
Want to learn more about growing impatiens?
Check out these Web sites chosen by us for more information on the subject:
Clemson University in South Carolina has a guide to impatiens.
Some of impatiens’ history and preferences are explained in this University of Vermont Extension article.