Gardeners have been planting Impatiens in shady spots for decades. There are now 850-species of these sweet, flowering, members of the Balsam family. Their common names (Touch-Me-Not, Garden Balsam, Balsamina, Busy Lizzie and Patience Plant) come from their seedpods “impatiently” exploding when touched.
The familiar, shade-loving Impatiens, Impatiens walleriana, is perennial in its native east Africa and most gardeners north of Africa treat them as annuals, allowing them to die at the end of each season. They are easy to over-winter indoors or start from seed, and stem-cuttings root quickly in water.
Thompson & Morgan (tmseeds.com) sells Impatiens seeds as I. Walleriana and I. Balsamia on their U.S. site and as Busy Lizzie on their British site.
The Royal Horticultural Society awarded Garden Merit status to several Impatiens including: Accent Series (8-inches tall), Blackberry Ice, Elfin White and Red, Super Elfin, Fiesta Ole and Wink and Blink. Super Elfin from Costa Rica is the one usually sold in garden centers. The plants are spreading and flat (10-in tall) in colors from pastels to violet and red.
One seed catalog, Swallowtail Gardens, offers seeds of 60 Impatiens varieties (www.swallowtailgardenseeds.com). Start the seeds mid-March inside on a heat mat (60-65 degrees F) in a sunny window sill.
New Guinea Impatiens, Impatiens hybrida I Hawkeri, introduced in 1972, did not catch on with the public right away but now there are hundreds of cultivars, leaf forms and flower colors for window boxes, hanging planters, landscape beds, etc. They are perennials in zones 9 to 15 and grown as annuals elsewhere.
Most New Guinea Impatiens hawkeri are grown from cuttings but they can also be started from seed. Harris Seed (harrisseed.com) offers 8 seed varieties from the disease-resistant Divine Series.
Start New Guinea Impatiens seeds indoors under warm conditions where the seedlings can develop strong root systems. Once established, transplant them into packs or pots. Plant outside in part-shade after all danger of frost has passed.
SunPatiens (www.sunpatiens.com) are the new stars of the Impatiens genus since they thrive in our now-hotter climates, resist mildew from humidity, and can take full sun.
A single plant in the award-winning spreading SunPatiens series replaces 4 traditional plants and grows 30-inches tall (americangardenaward.com). The Compact Series has a 2-foot-mounded habit.
SunPatiens, a hybrid of the old-fashioned Impatiens walleriana and New Guinea impatiens (Impatiens hawkeri), have thicker leaves and stronger stems.
They were a huge success at the Dallas Arboretum Plant Trials (www.dallasplanttrials.org). Four-inch pots were planted in the sunniest, hottest, section of the trial garden where they would not receive even filtered shade in the Dallas summer. They thrived, growing and blooming all season.
SunPatiens are available in upright and spreading forms with flower colors in white, lilac, coral, rose, red and magenta. The spent flowers do not have to be removed to keep the plants blooming and the stems can be pinched back to renew them for thicker growth and shorter plants.
In the Dallas trials the best plants were the white, orange, and magenta, which grew 2-feet tall.
SunPatiens want full-sun or a minimum of full-afternoon-sun. For beds with less light, use regular shade-loving Impatiens or one of the half-shade hybrids.
Whether in the shade, half-shade or full sun, all Impatiens require regular water but try not to drown them. Allowed to dry out to the point of wilting before watering, they will flower more and remain more compact.
SunPatiens grow 2-3 feet tall with 2-3 inch flowers. No trimming is necessary but you can prune them for shaping.
For shade choose Impatiens walleriana; for part-sun plant New Guinea Impatiens and in afternoon or full-sun fill the bed or containers with SunPatiens.