<em>Impatiens</em>, Sunpatiens: planting, sowing and care

Description and botany

Impatiens, also called Busy Lizzie or Balsam is a perennial herbaceous plant belonging to family Balsaminaceae, native to marshy forests and moist, shaded places in tropical and warm temperate regions.

Frost-tender, it is grown as an annual in the garden in our latitudes or as a houseplant because this non-hardy perennial cannot withstand our winters and dies at first frosts.

Genus includes more than 900 species. Oldest species cultivated in gardens is Impatiens balsamina, the garden balsam, which has produced numerous cultivars, notably double camellia-type flowers. Also commonly grown are Impatiens walleriana and its hybrids, and Impatiens niamniamensis, the striking “parrot’s beak” from Congo, which bears spurred flowers and also occurs in several varieties.

Hybridization work has produced, among others, the well-known SunPatiens® (Impatiens x hawkeri), hybrids partly derived from Impatiens hawkeri of New Guinea, now indispensable because more tolerant of sun, such as the ‘Compact’ series.

Fast-growing, Impatiens forms in a few months a bushy clump about 25 to 80 cm high on average with nearly the same spread. While a few species such as I. glandulifera (Himalayan balsam) can climb to 2 m and others are creeping like Impatiens repens, most of the new hybrids available offer a neat, compact, often highly ramified habit.

Hybrids of I. walleriana display a more spreading habit. While most impatiens cannot be grown in the open ground because of their tender nature, Impatiens arguta has a more vigorous crown with tuberous roots that can withstand temperatures of about −12 to −15 °C.

Stems easily broken, almost succulent, thick and stiff, sometimes flushed red, carry many alternate, opposite or whorled leaves 2 to 20 cm long on a long petiole. Generally narrow, ovate or elliptical with a pointed tip, lamina crenate and slightly dentate, leaves are pale to dark green. Some varieties, notably New Guinea types, show very decorative foliage tinged bronze, yellow or variegated.

Some flowers: Impatiens Compact Hot Lilac, Impatiens puberula, Impatiens Compact Orchid Blush, Impatiens Compact White, Impatiens niamniamensis

This lush foliage, fleshy and glossy, sometimes slightly translucent, is indeed covered with numerous flowers from June until first frosts in the garden or throughout year indoors away from frost. From late spring, long-pedicellate flowers appear singly in the axil of leaves or grouped in small clusters of 2 to 6, and are produced repeatedly until autumn.

They measure 2 to 6 cm in diameter and are made of five heart-shaped petals. Semi-double or double, resembling tiny, chubby camellias, single and flat, sometimes helmet-shaped or armed with a curved spur as in the very singular Impatiens niamniamensis with hooked flowers evoking parrot beaks, flower form varies with variety and hybrids.

Monochrome or bicolour, they offer an endless range of bright, sparkling hues, perfectly set off by dense foliage.

Shades range from pastel to almost garish: pure white, purple, lavender blue through all shades of pink and red, scarlet, crimson to yellow or coral. With a silky, velvety texture, petals of some impatiens are subtly marbled or marginate or bear a throat maculate in contrasting tone.

This extremely generous flowering, sometimes slightly scented, gives way in autumn to dehiscent fruits that burst open suddenly, forcefully ejecting their seeds when ripe; it is this impatience to fling seeds far and wide that gave the plant its name Impatiens!

This tender perennial cannot tolerate negative temperatures, which is why, in our climate, it is grown as an annual in the ground or in pots. While impatiens have long favoured semi-shaded or shaded locations, new hybrids such as SunPatiens® now tolerate full sun very well and adapt to both cool climates and our warmest regions.

In moist, fertile soil, Impatiens offers unrivalled flowering and is almost maintenance-free!

With their fresh or lively colours, these summer flowers are ideal for shaded garden scenes, enlivening summer displays in beds, as borders along a path or wall, at edge of a woodland, in a window box on a sill or in containers on a terrace or by doorways.

Impatiens are believed to have air-purifying qualities.

Main species and varieties

Most popular

Our favourites

Another interesting variety

Impatiens Sunpatiens Compact Blush Pink - Busy Lizzie

A very floriferous Impatiens considered one of the best. It tolerates sun and will form a ball of flowers in pots or in your summer beds.

• Flowering time July to November
• Height at maturity 25 cm

See the product sheet

Impatiens SunPatiens Compact Purple

A hybrid impatiens with vibrant, intense hues from June until first frosts. Plant in window boxes or along paths in full sun.

• Flowering time July to October
• Height at maturity 60 cm

See the product sheet

Impatiens niamniamensis

A tender, highly unusual perennial, producing strange bicolour flowers. It provides an exotic display in shaded beds or, kept warm, indoors or in the conservatory, even in mid-winter.

• Flowering time July to December
• Height at maturity 60 cm

See the product sheet

Impatiens Sunpatiens Compact Hot Lilac - Busy Lizzie

A hybrid impatiens covered in vivid lilac-pink flowers for six months. Ideal for summer arrangements thanks to its compact habit.

• Flowering time July to November
• Height at maturity 40 cm

See the product sheet

Impatiens Sunpatiens Compact Electric Orange

A hybrid variety with a compact habit and a brilliant orange colour. Perfect for summer compositions — in window boxes, along pathways, in planters and bed borders.

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Impatiens Sunpatiens Compact Orchid Blush - Busy Lizzie

We love its delicate pale mauve-pink flowers. Charming in planters and bed borders.

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Selection of 5 Sunpatiens Impatiens

An exclusive collection of five Impatiens resistant to disease and sun! Well suited to beds, pots, borders and planters.

• Flowering time July to November
• Height at maturity 25 cm

See the product sheet

Impatiens walleriana F2 Colour Cocktail Mix - Busy Lizzie

A charming mix of impatiens to brighten shaded areas with their brightly coloured flowers. Easy to sow in beds and shaded borders; never in full sun.

• Flowering time July to November
• Height at maturity 20 cm

See the product sheet

Impatiens puberula

One of the few perennial impatiens! Very unusual, it is fully hardy in your garden.

• Flowering time August to November
• Height at maturity 15 cm

See the product sheet

Planting

Where to plant Impatiens?

Impatiens is a frost-tender perennial plant that does not tolerate sub-zero temperatures and must be brought indoors for winter because it dies at 0°C. That is why it is grown in the garden as an annual in open ground, dying back at first frosts, or kept as a tender perennial houseplant (keep warm in winter at a minimum of 10–15 °C) offering flowering all year round.

You can move containers outside in fine weather as soon as temperatures rise above 15 °C and frosts are no longer a risk.

Even though recent hybrid varieties tolerate sun better, Impatiens remains one of the best choices among summer shade flowers, the only annual capable of flowering in full shade. Hybrids tolerate non-burning exposures fairly well if their roots stay cool during summer.

In containers outdoors, protect from wind.

As with any tropical plant, it prefers humid environments and is particularly at ease in a greenhouse or conservatory with filtered light and no direct sun, protected from drafts.

It is easy to grow in fresh, humus-bearing and well-drained soil because it tolerates neither drought nor stagnant moisture.

An outstanding summer and shade flower to flower throughout the season in cool, shaded corners of the garden, impatiens can be planted indifferently in pots or window boxes as well as in open ground, in groups on the edge of a bed of bushes, perennials or annuals, at edge of a woodland, to punctuate ephemeral path edges. Low cultivars (10 to 15 cm high) or new hybrids with a very compact habit make beautiful groundcovers.

They also make good indoor plants for conservatory and can accompany you for many years.

Impatiens are excellent groundcovers for shade!

When to plant Impatiens?

Planting of our Impatiens plug plants is done in spring from April to May, or even June depending on region, in all cases after last frosts, in open ground or in pots. Planting under cover is possible from March.

How to plant Impatiens?

On receipt, pot up and keep our Impatiens plug plants under cover and allow them to gain strength for a few weeks before placing outside once frost risk has passed.

In open ground

Allow about 8 to 10 plants per m2, spaced at least 20 cm apart in all directions. You can plant in numbers to obtain large flowering carpets under trees for example. Plant in staggered rows. Soil must be fertile and well-drained.

• Fork over soil to half spade depth
• Dig a hole 2 to 3 times the size of the plug (about 15 cm deep)
• Make a good bed of gravel for perfect drainage
• Mix excavated soil with geranium potting compost and coarse sand
• Place plug plant in centre of hole, with collar at soil level
• Backfill to surround roots
• Firm with foot
• Water generously

In pots

Most impatiens are the kings of window boxes and summer containers! Mix varieties! Space plug plants 20–25 cm apart for a dense, lively composition.

• Soak plugs well before planting
• Line base of container with gravel or clay pebbles
• Plant in geranium-type potting compost mixed with river sand. Fill gaps
• Firm gently without damaging the plug
• Water well then regularly but without excess as soon as surface soil dries
• Store pot in autumn away from frost if you want to grow as a perennial and bring out in May, avoiding too-strong sun

More tips on our blog for successful planting plug plants in window boxes!

Impatiens Compact Lilac in a pot

When and how to sow Impatiens seeds?

Under cover

Sow the impatiens seeds from March under heated cover. Your plants will flower after about 6 weeks.

• In a seed tray, sow seeds on surface without covering, in a mix of potting compost and heather soil
• Place in bright light in a warm spot at 16–21°C
• Keep growing medium moist but not waterlogged until germination, about 18–21 days
• Keep seedlings warm until mid-May
• Plant out into open ground, spacing plants 30 cm apart, or into pots or window boxes after all risk of frost has passed, adding compost to each planting hole

Direct sowing

• In May, in well-worked soil enriched with potting compost, broadcast impatiens seeds once all risk of frost has passed
• Cover lightly with potting compost without burying
• Firm down
• Water well with a fine spray
• Thin seedlings, leaving one young plant every 30 to 50 cm
• Pinch out stem tips to encourage young impatiens to ramify

→ Learn more in our tutorial : How to sow impatiens ?

Maintenance, pruning and care

Impatiens is an annual, floriferous, trouble-free and above all almost maintenance-free plant — provided it is regularly fed with fertiliser and well watered!

In the ground

Impatiens does not tolerate drought. Watering should be regular, especially when it does not rain and weather is dry, without being excessive — once or twice a week — because its roots are sensitive to excess moisture, which causes root rot.

Remove faded flowers and dry stems regularly to keep plant looking good and to stimulate flowering.

Very tender, plant will perish with first frosts and must be renewed each year in the garden: pull up clumps unless you wish to keep them. In that case, cut plant back to ground level, pot up and restore in a frost-free, warm place out of direct sunlight: indoors, flowering is almost continuous when pot is kept above 15°C.

Impatiens Compact White

Caring for an impatiens in a pot

With rapid growth, it is hungry: water once a week, allowing soil to dry between waterings to avoid any risk of rot; likewise, do not let water stand in saucers.

Indoors, ensure high humidity as foliage and flowers wilt quickly if ambient air is too dry: optionally place pots on a bed of clay pebbles to increase air humidity this tropical plant needs indoors.

Apply a liquid fertiliser once or twice a month during growth. Water sparingly in winter but do not let the rootball dry out and keep room temperature between 10–15°C.

Pruning is not necessary; impatiens naturally retains a lovely compact, rounded habit: in spring, simply cut back shoots that tend to become bare at the base to encourage new shoots and renew flowering.

Repot every two years if necessary in spring and give it a spell outdoors in the garden in a shady position from May to September. You can also transplant it into the ground for the summer season within a shaded flowerbed or border.

Possible diseases and pests

Disease-resistant, impatiens are hardy. Outdoors, remember to protect them from slugs which enjoy their young foliage and read our tips for keeping gastropods away!

Avoid excess water which can cause grey mould (Botrytis) of the collar, main stem and flower buds: always let the soil dry out between waterings. If affected: repot into a free-draining, not waterlogged mix and water sparingly.

Impatiens grown in greenhouse or conservatory are sensitive to red spider mites that develop in warm, dry conditions and cause leaves to yellow and drop: mist the foliage regularly with non-calcareous water to maintain a humid environment around the pot to help prevent attack. If infestation occurs: carry out sprays of soapy water.

Indoors, they may also be attacked by aphids and whiteflies (whiteflies) during summer: prune back heavily infested stems and spray with soapy, non-calcareous water.

Propagation

Self-seeding is common; impatiens seeds readily self-sow when conditions are favourable. If propagation of impatiens can be done by sowing (with seeds harvested in autumn), propagation by cuttings using herbaceous cuttings in May–June remains a quick and simple way to obtain new plants.

How to take cuttings of Impatiens?

• Take stem cuttings 7–10 cm long
• Place them in a glass of water indoors
• After two–three weeks, when roots have appeared, replant cuttings into buckets filled with moist turf and coarse sand
• Keep warm and frost-free over winter (minimum 15°C) and pot on the following spring into open ground or into pots after last frosts

Companion planting with Impatiens

With their bright or pastel colours, Impatiens are among those annuals essential in summer for shaded garden scenes, bringing cheer and charm.

An idea for a shaded planting combination: Digitalis purpurea, Hydrangea macrophylla ‘Black Steel Zebra’, Impatiens Compact White, Polystichum setiferum ‘Proliferum’, Geranium nodosum

They fit easily into city gardens, natural or naturalistic gardens or romantic gardens, creating bright, fresh and often very colourful compositions. With them, shade is not always a sign of dull or washed-out colours!

In groups, they are easy to combine with other summer-flowering shade or partial-shade perennials or annuals, quickly forming striking, colourful masses alongside Astrances, Japanese Anemones, Fuchsias and Ammi.

Impatiens rival in beauty with plants of bronze, silver and yellow-green foliage, marrying harmoniously with Anthirrhinum, Diascias, Helichrysum petiolare, tobaccos and spreading-habit verbenas.

An idea for a windowbox combination: Impatiens Compact Hot Lilac, Heuchera ‘Purple Petticoats’ and Impatiens Compact Orchid Blush

Plant them in the foreground of a border with small grasses such as fescues.

In a woodland setting, punctuate a tapetum of Heucheras and Hostas with a few Impatiens plants and mix them with bulbs to naturalise for shade!

Paired with Hydrangeas and pelargoniums, they will hide bare bases of shrub roses throughout the season in a fresh, romantic picture of a pink garden or white garden.

In pots on a shaded terrace, mix them with other annuals such as coleus, begonias or morning glories.