Impatiens are an annual and shine in a shady border. They are easily grown from stem cuttings and have a low, compact mounding habit. You can try growing the plants from seeds, but they are a bit difficult. They prefer part shade to full shade; one of the few plants willing to flower under such conditions. Here in central Florida they bloom profusely whenever the weather isn't baking hot. This means I have blooms from November through May. After that, they begin to look a little hung over. And, when it gets really hot in June, July, August and September, you're better off cutting them back to about 6 inches of bare and spikey and letting them sulk through the heat and humidity.
For two years now, I've lined the sidewalk in our small courtyard with bright rose impatiens and they've been a delight to behold. It makes the entry to the house vivid and colorful. In 2002, I also underplanted an Australian tree fern on the other side of the walkway with the same shade of impatiens for balance.
Impatiens have thick, succulent stems that must be kept full of water. They droop quickly once they get thirsty. I want to say they are better off in the ground, although during the winter and spring they can be captivating and graceful in a basket or window box. This past growing season (2001-2002) I did fill several hanging baskets and window boxes with impatiens and they bloomed nonstop for about six months.
The New Guinea impatiens can tolerate more sun (I'm talking winter sun here, not summer sun) and are vigorous growers. This strain is one of the most appealing plants available for the shady and dappled sun garden. Leaves have a bolder look than that of regular impatiens and come in a variety of colors. The flowers are large, luminous and stunning. This plant, too, is easily propagated with stem cuttings, but growing it from seed is reportedly quite challenging.