Touch-me-not balsam

Impatiens noli-tangere

In other languages: Groot springzaad (Nederlands) · Balsamine des bois (Français)

Grows wild in Belgium.

Touch-me-not balsam is a native annual of damp, shady broadleaved woodland, stream banks, alder carr and spring-fed ground on humus-rich, fertile soil. In Belgium it is fairly rare: you find it mainly in Wallonia, with scattered sites in damp woods in Flanders. You can recognise it by its juicy, translucent stems with swollen nodes, its thin, coarsely toothed leaves and above all by its hanging, lemon-yellow flowers with a curled spur and red-brown spots inside. Ripe fruits burst open at the slightest touch and shoot out their seeds, hence the name. Bumblebees visit the flowers, and in Europe it is the only food plant of the caterpillar of a rare moth.

Caution: Touch-me-not balsam is mildly poisonous: do not let children or pets eat it. Do not confuse it with Himalayan balsam, which is on the EU list of invasive species and must not be planted or spread.

Updated on 9 October 2026

Light
Partial shade or shade
tolerates little sun
Moisture
Normal to wet
must not dry out
Hardiness
Fully hardy
down to -25 °C
Size
0.8 m
tall, 0.4 m wide
Flowering
July–September

Key facts
Height	0.8 m
Native to Belgium	Yes
Flowering	July–September

Identify

How to recognise it

Habit: Hairless annual, 30–100 cm tall, with an upright, branched stem and a shallow root system.
Leaf: Alternate, oval to elliptical, 5–12 cm long, thin, bluish green and hairless, with a coarsely toothed margin.
Flower: Hanging on slender stalks below the leaves, lemon yellow, 2–3.5 cm long, with a wide throat full of red-brown spots and a spur that is curled at the tip. The plant also produces small closed flowers that pollinate themselves.
Fruit/Seed: An elongated green capsule 2–3 cm long. When ripe it bursts open at a touch: the valves curl up in a flash and shoot the seeds up to a few metres away.
Stem: Juicy, glassy and translucent, brittle and hairless, with swollen nodes; it snaps easily.
Look-alikes: Small balsam, a non-native species that is much more common, has small, pale yellow, upright flowers with a straight spur. Orange balsam from North America has orange flowers with red spots. Himalayan balsam grows up to 2.5 m tall, has pink to purple flowers and is on the EU list of invasive species.

Flowering: July–September

In your garden

Why grow it?

One of our few native balsams: with its hanging yellow flowers it is an eye-catcher in a damp, shady garden.
Bumblebees crawl into the flowers to reach the nectar in the spur and pollinate them as they do.
The caterpillar of the netted carpet moth (Eustroma reticulata) feeds only on this plant.
It flowers in summer in wet, shady places where few other plants flower so conspicuously.
The exploding fruits are a game for children and a fine example of how plants scatter their seed.

Touch-me-not balsam: where does it grow best?

In the wild: damp to wet broadleaved woodland, alder and ash woods, stream banks, seepages and springs, often with ferns.
It needs humus-rich, fertile soil that never dries out, in partial to full shade.
In the garden: a damp, shaded corner under trees, along a stream or pond edge, or in a wet shade border.
In full sun and on dry soil it wilts quickly and disappears.

Goes well with

Lady fern: Fine, light green fronds in the same damp, shady spot.
Enchanter’s nightshade: Tiny white flowers in summer under trees, on humus-rich soil.
Meadowsweet: Creamy, scented plumes in summer along a stream or pond edge.
Marsh-marigold: Golden-yellow flowers in spring, long before the balsam flowers.
Opposite-leaved golden-saxifrage: A low green carpet with tiny yellow flowers on wet, shaded ground.

Maintenance

Touch-me-not balsam: when and how to plant it?

Buy seed from a nursery specialising in native plants and check that it really is touch-me-not balsam and not a non-native balsam. Never take plants or seed from the wild.
Sow in September–November, using seed as fresh as possible, in place or in pots left outside: the seed needs a cold winter to germinate. Cover it with a thin layer of soil.
The seedlings appear early in spring, often as early as March.
In April, thin or move the young seedlings to 25–30 cm apart, with a small root ball. Moving them later rarely works because of the brittle stems.
Keep the soil moist, especially during dry spells in spring and summer.
Because it is annual, it has to re-seed every year: let the fruits ripen and keep a few bare patches open.

Care

Watering: The soil must always stay moist. Water in dry summers, preferably with rainwater; in drought it immediately lets its leaves droop.
Feeding: Not needed: a thin layer of leaf mould or fallen leaves keeps the soil rich enough in humus.
Leaf litter: Leave a thin layer of fallen leaves: it keeps the soil moist. In February, rake a thick layer off the spots where it should germinate.
Self-seeding: Leave the plants after flowering until the fruits have burst open. Do not tidy them away.
Competition: Keep nettles and small balsam in check, so the seedlings get light and space in spring.

Tip: Sow touch-me-not balsam in autumn, right after collecting the seed, in a damp, shady spot: it germinates by itself after winter and then keeps itself going year after year.

Pruning and mowing

When: No pruning needed: it is an annual that dies naturally after setting seed.

How:

Leave the plants until the fruits have burst open and the seed has been scattered.
Leave the dead stems where they fall: they quickly rot down into humus.
At most, remove stems that hang over a path, but only after the seed has been shed.

Caution: Do not tidy up in summer or early autumn: you would lose next year’s seed.

Pruning calendar and basic rules

Propagation

Seed: The only method. Collect ripe fruits in August–September by holding a paper bag around them and then touching them. Sow outside straight away: fresh seed germinates best.
Self-sown seedlings: In a good spot it maintains itself every year and slowly spreads around the original plants.

Touch-me-not balsam: how does it get through the winter?

Hardy to −25 °C.

The plant dies at the first night frost; it overwinters only as seed in the soil.
The seed is fully hardy and even needs winter cold to germinate in spring.
The decaying stems and leaves become humus that keeps the soil moist and fertile.

Diseases and pests

Wilting: In drought or too much sun it goes limp. Water it and choose a damper, shadier spot.
Slugs: They like to eat the young seedlings in spring. Sow generously and let toads and ground beetles do their work.
Aphids: On the shoot tips in summer. Ladybirds and hoverfly larvae usually clear them up.
Non-native balsams: Small balsam and Himalayan balsam can take over the same places. Pull them up before they set seed, and always check what you sow.

Through the year

March: Seedlings appear. Protect them against slugs.
April: Thin or move the seedlings.
May: The plants grow fast. Water in dry spells.
June: First buds. Pull up small balsam.
July: Flowering. Bumblebees visit the yellow flowers.
August: Full flower and first ripe fruits bursting open.
September: Last flowers. Collect seed and sow it straight away.
October: Sow. The plants die back at the first frost.
November: Last chance to sow. Let the stems rot down.

You and this species

Did you know?

Noli me tangere is Latin for ‘do not touch me’, the words Jesus spoke to Mary Magdalene according to the Gospel of John. The genus name Impatiens, ‘impatient’, also refers to the fruits that burst open when touched.
Besides the large yellow flowers, the plant also makes small flowers that never open and pollinate themselves; that way it sets seed even in deep shade.
Small balsam, its non-native relative from Central Asia, escaped from botanic gardens in the 19th century and is now far more common than the native species in many woods.

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