There seems to be some confusion in the minds of folks about the different forms of impatiens out in the gardens right now, so this brief article is intended to set the record straight. To begin with, there are approximately 36 species of impatiens in the world and while this number could be up or down a few depending on what the taxonomists have done recently, the family shares a common thread of cultivation needs.
Where Impatiens Like To Grow
For the most part they are found in light woodland areas, growing in rich but well drained, humus rich soils in cool sites. They require constant moisture levels but not standing water. (The exception to that is I. mirabilis but you won’t likely find its seed anywhere anyway) All forms are frost tender and do not survive winter of any kind. Lets go down the list and outline the various plants you’ll find.
The Most Common Garden Impatiens
Variously known as Impatiens walleriana, Impatiens, Busy Lizzie, Patience Plant, Sultana and probably a few other names I haven’t heard of yet.
This is the impatiens of the garden centre.
Flowering all summer in shady, cool, areas.
The number one bedding plant in North America – some 15 million flats of them sold every spring with 40-72 plants per flat.
There are many cultivars including doubles, variegated leaves, uprights, tall, etc. etc. but all are best grown in good soil in regularly damp shade conditions.
They can be pinched back to encourage bushiness or planted slightly closer than the tag to encourage them to grow much taller than listed on the tag.
Grow in hanging baskets or containers as long as you give adequate moisture. They will handle more sunshine if you keep them well watered (dry sunny spots are a death sentence) but they are not plants of the full sun garden.
These are the most garden-important of the family. Simply remember that they all prefer the moist, cool, indirect lighting of the forest floor and you’ll grow them to perfection.
Propagation: cuttings are easy and seed germinates within 5-10 days if you have bottom heat and do not cover the seed.
New Guinea Impatiens ‘Paradise Electric’
The Second Most Common: New Guinea Impatiens
I. hawkeri are also known as New Guinea Impatiens and Sunshine Impatiens. There are a great many cultivars of this form on the market right now leading to some spectacular failures in the garden.
This species likes the same conditions as the rest of the family (shade to semi-shade) but it is being marketed as a plant that can tolerate straight sunshine.
Withhold water from this plant for 24 hour and watch the leaves turn brown.
This demands constant moisture and protection from the scalding sun if it is to do its best.
Turf it out in the full sun and water sporadically – a guaranteed recipe for garden disaster.
Available in most garden centres. The cutting propagated forms are the best garden performers.
Propagation: Roots from cuttings.
Other Lesser Known Impatiens Plants
I. balsamina is the Garden Balsam so beloved of Victorian ladies.
(Garden Balsam or Rose Balsam) Various cultivars ranging from 12-24 inches tall exist and the plant has been often successfully grown as a houseplant. Easily started with soil in the 72F range and constant but not excessive moisture, the plant is a quick grower flowering from seed in as little as 2 months. Cuttings of outstanding plants are easily rooted (as are most of the family) and grown on. Flower colours tend to the pastels in the red spectrum.
I. capensis (Jewelweed, Lady’s Earrings, Orange Balsam)
This is one of the taller of the North American species reaching a height of 4-5 feet tall. Again, it grows in semi shaded areas in moist but well drained soils. Mostly the flowers are an orange yellow but there are some white cultivars out there being grown by collectors.
I glandulifera is known Policeman’s Helmet, Himalayan Balsam
A taller form, reaching 3-6 feet tall. The flowers are rose purple to lavender with a few white tones thrown in for good measure. Native to the Himalayas, it has naturalized in some parts of Northern North America. This one can get weedy if left unchecked in warmer areas.
I. noli-tangere (Touch Me Not)
A European native, this upright form (12-36″) is sometimes found in seed exchanges or specialist seed catalogues.
Yellow with interior red spots, the flower is interesting but not spectacular. Seed pods explode (as do most of the species) when ripe and a casual touch on a ripe seed pod can be quite entertaining as the pods explodes sending seeds everywhere.