Small balsam

How to recognise it

Habit

Upright annual of 20–60 cm, sometimes up to 1 m, with juicy, hairless, slightly translucent stems.

Leaf

Alternate, oval to elliptical, 5–15 cm, pale green, with a finely toothed edge and a pointed tip.

Flower

Small, 5–15 mm, pale yellow and funnel-shaped with a short, straight spur, in small clusters above the leaves, from June to October.

Fruit/Seed

Slender, club-shaped pod of 1.5–2 cm that bursts open when ripe or touched and flings the seeds up to a few metres.

Roots

Small and shallow: the plant is easy to pull up.

Confused with

Touch-me-not balsam is native, has much larger, golden-yellow flowers of 2–3.5 cm with red spots and a curved spur, and grows in wet woods. Himalayan balsam has large pink flowers, grows 1–2.5 m tall and is on the EU list of invasive species. Orange balsam has orange flowers with red spots.

Flowering: June–October · Pruning: June–July

Why grow it?

• Flowers from June into October in shade, where few other flowers grow.
• Hoverflies and small bees collect nectar and pollen from the little flowers.
• The exploding seed pods are a fun discovery for children.
• Temporarily covers bare, shady ground under trees with fresh green.
• An instructive example of a non-native plant that has become naturalised in our woods.
• To be honest: for wildlife it is worth less than native woodland plants such as touch-me-not balsam.

Small balsam: where does it grow best?

• In the wild: broadleaved woods, poplar and ash woods, parks, hedgerows, woodland edges and shady verges.
• Partial to deep shade; in full sun it stays small.
• Moisture-retentive, humus-rich soil; on fertile soil it grows larger.
• In the garden: it often appears on its own under shrubs and trees, in a shady border or between the paving on the shady side of the house.

Goes well with

• Touch-me-not balsam: The native relative with large yellow flowers, for a damp, shady spot.
• Herb-Robert: Small pink flowers in shade, also popular with small bees.
• Hedge woundwort: Purple spikes in partial shade, an excellent native alternative.
• Greater stitchwort: White stars in spring, before the balsam comes up.

Small balsam: when and how to plant it?

1. You do not need to plant small balsam: it often arrives by itself with soil, potted plants or seed from nearby.
2. For a shady wildlife garden, choose native woodland plants instead, such as touch-me-not balsam, wood anemone or greater stitchwort, from a nursery for native plants.
3. If you still want to keep it, let a few plants ripen in a shady spot where they do no harm; they will self-sow.
4. Never take seed or plants to woods, parks or nature reserves: there it competes with the native woodland flora.
5. Never dig up wild plants in woodland; buy woodland plants from a nursery.

Care

Water

Not needed. In a long drought it wilts, but it recovers after rain.

Feeding

Not needed; on rich soil it grows larger and self-sows more.

Spreading

Pull plants out by hand before they set seed, ideally in June–July; the shallow roots make this easy.

Letting it seed

Only leave plants where they do no harm: each plant produces a lot of seed.

Disposal

Pulled plants without ripe pods can go on the compost heap; with pods, the green waste bin is better.

Tip: Pull up small balsam in June, when the first flowers make it easy to recognise and before the pods ripen: within a few years you will have it well under control.

Pruning and mowing

Pruning months: June–July.

When: In June–July, before the seed pods ripen.

How:

• Pull the plants up, roots and all; there is no need to cut.
• Do it before the first pods burst: after that you only spread the seed.
• Repeat for several years in a row, until the store of seed in the soil is used up.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

The ripe pods burst and fling the seeds a few metres. That is how it spreads further every year.

Spread

People, animals, water and moved soil or potted plants carry the seed further; bear this in mind when you give away soil or plants.

Small balsam: how does it get through the winter?

Hardy to 0 °C: protect in harsh winters.

• The plant dies at the first night frost: it is a true annual.
• The seed overwinters in the soil and needs the cold to germinate in spring.
• As early as March–April, masses of seedlings appear, each with two rounded seed leaves.

Diseases and pests

• Self-sowing: The main problem: it forms dense carpets. Pulling it out before seed set keeps it in check.
• Mix-up with Himalayan balsam: Young plants look alike. Himalayan balsam has opposite or whorled leaves with small reddish teeth; always pull it out and dispose of it.
• Aphids: Sometimes on the stem tips; ladybirds and hoverfly larvae usually deal with them.
• Wilting in heat: It wilts quickly in hot, dry weather. It recovers in the evening or after rain.

Through the year

• March: The seedlings germinate.
• April: Weed out seedlings where you do not want them.
• May: Fast growth in the shade.
• June: First small yellow flowers; start pulling.
• July: In flower; pull up before the pods ripen.
• August: The pods burst open when touched.
• September: Still flowers and seed.
• October: Last flowers.
• November: The plants die after the first frost.

Did you know?

• Impatiens means ‘impatient’: the ripe pods burst open at the slightest touch.
• Parviflora means ‘small-flowered’: it has the smallest flowers of the balsams in our region.
• It escaped from botanic gardens in the 19th century and has since become naturalised across much of Europe.