Impatiens provide generous amounts of vibrant color for many months. They are easy to grow and are currently available in every color except blue. Depending on the variety, impatiens can fill a number of useful niches: dwarf impatiens to edge pathways; New Guineas to add color in shade (light and dark) to monochromatic areas; all work well in patio containers and make good border and bedding plants, shade windowbox fillers and hanging basket plants. Some species (I. capensis) will self-sow.
As you might imagine with plants native to India and Africa, impatiens have difficulty with cold weather. Ideally they should be placed in the garden after danger from the last frost has passed.
When planting impatiens use a rich, moisture-retentive soil that will drain well. Mix in large amounts of organic matter and compost. Fertilize by mixing in a dry product such as Dr. Earth or by watering with one of the liquid fertilizers, such as Grow-More, once a month or 1/2 strength twice a month. Over-fertilized impatiens can become droopy and “leggy.” When impatiens begin to appear leggy or stretched out, pinch or prune them back to encourage leaf and bud growth and general fullness on the lower stems. Make sure some leaves remain on each plant.
Impatiens may be seen growing in full sun (with generous watering) but they are first and foremost full to light shade plants. New Guinea Impatiens grow best in light shade to moderate (not western) sun. Satisfied with their environments, impatiens can bloom and prosper until the frost takes its wintery toll.
Impatiens balsamina This is a true annual from India, China and the Malay peninsula. Garden balsam or topknot plant grows 12 to 24 inches high producing large single or double flowers in pink, white, salmon scarlet or purple. Flowers are carried along the main stems, jutting out from the leaf axils. There is a dwarf form 8 to 12 inches tall.
Also called Jewelweed or Touch-Me-Not. Helmet-shaped blooms of white, yellow or lilac pink on stalks to 6” tall bloom through the summer. The name “Touch-Me-Not” refers to the habit of the plant’s ripe seed pods exploding and expelling seeds when touched.
I. glandulifolia (previously known as I. roylei)
Pale rosy lavender bloom clusters are slightly fragrant on this tall (2 to 6 feet) impatiens. Himalayan Jewelweed is best when grown in the middle of a mixed bed where its long stems can be hidden.
I. New Guinea
These bold colorful plants are perennials in New Guinea and are grown in the Pacific Northwest as summer annuals. Look for a floral palette of whites, pinks, reds, oranges, lavenders and violets. Handsome elliptical shaped leaves may be dark or bright green or variegated with bronze, red, cream or lemon. Variegated-leaf varieties need more shade than those with simple green leaves. Varieties range in height from 8 to 24 inches. Plant approximately 8 to 10 inches apart. “Fireflies” are a recent addition to the New Guinea family. They are a dwarf form and have petite leaves with a myriad of bright, petite blooms. Baby Bonitas are the earliest of the New Guineas to flower. They produce compact mounds of colorful blooms for mixed containers and color bowls.
Double impatiens are best when planted in containers where their rose-like blooms can be appreciated at close range. Leaves may be green or variegated green and cream. Series like Tioga or Fiesta have a height range of 8 to 10 and 10 to 12 inches respectively. Spread will be 8 to 10 inches.
A recent introduction. Somewhat tri-lobe shaped blooms (which appear to be triangular from a distance) are borne on compact plants to 12 inches high. Tropical colors of yellow, peachy lemon, apricot and papaya were bred from yellow African impatiens and are best
grown in containers.