Herb-Robert

How to recognise it

Habit

Annual or biennial, loose, bushy plant 10–40 cm tall, often wider than it is tall.

Leaf

Palmate, divided into three to five deeply cut and further lobed segments, somewhat fern-like. Fresh green, turning red in sun and in autumn.

Flower

Pink, about 1.5 cm across, with five rounded petals striped with white and orange to purple anthers. Usually in pairs on one stalk.

Fruit/Seed

A long beak about 2 cm long, like a stork’s bill. When ripe, the segments spring apart and the seeds are flung a few metres away.

Stem

Reddish, brittle, with spreading glandular hairs; when crushed, the whole plant smells unpleasant.

Look-alikes

Little-Robin has smaller flowers with yellow anthers, is rarer and grows in dry, stony places. Dove’s-foot crane’s-bill and cut-leaved crane’s-bill have smaller flowers with notched petals and no strong smell.

Flowering: April–October

Why grow it?

• Flowers for months, from April to October, with nectar for bees, bumblebees and hoverflies.
• Grows in the most difficult places: dry shade, walls, between stones and under hedges.
• The leaves turn a beautiful red in sun and in autumn.
• A natural groundcover for a woodland garden that keeps itself going.
• The fruits shoot out their seeds: a fun thing to watch with children.

Herb-Robert: where does it grow best?

• In the wild: woods, woodland edges, hedgerows, old walls, rocks, rubble and shady corners of towns and villages.
• Half shade to shade; in full sun it stays smaller and turns red.
• Almost any soil: from dry and stony to moist and humus-rich.
• In the garden: in a woodland garden, under hedges and shrubs, on a wall or between paving stones in a shady corner.

Goes well with

• Ivy-leaved toadflax: Lilac flowers on the same old wall.
• Male fern: Fresh green above the reddening herb-Robert in the shade.
• Woodruff: A white groundcover in the same woodland garden.
• Columbine: Also seeds itself in half shade and flowers in May.
• Ground-ivy: A low, creeping groundcover with small blue flowers.

Herb-Robert: when and how to plant it?

1. Buy seed or a plant from a native plant nursery, or simply let it arrive by itself: it seeds itself readily. Never dig plants up from the wild.
2. Sow in late summer or autumn where it is to grow; the seed often germinates only after winter.
3. Scatter the seed on loose soil and rake it in lightly.
4. Plant young plants in spring, 25–30 cm apart.
5. Water until the young plants have settled in.

Care

Water

Not needed, except for young plants in a dry spell.

Feeding

Not needed: it does fine on poor, stony soil.

Spreading

Seeds itself around, but is easy to pull out: the roots are shallow.

Self-seeding

Let the beaks ripen: the plant lives only one or two years and in this way keeps coming back every year.

Tip: Just let herb-Robert do its thing in the dry shade under a hedge: almost nothing else grows there, and it covers the ground from spring to autumn.

Pruning and mowing

When: Not needed. Just pull out surplus plants whenever you like.

How:

• Pull out plants where they are too crowded or smother other plants.
• In autumn, leave dead plants where they are, or pull them out if they look untidy.

Pruning calendar and basic rules

Propagation

Seed

Seeds itself readily. To sow it yourself: in late summer or autumn where it is to grow; it often germinates in spring.

Transplanting

In spring you can move young seedlings with a small root ball to a new spot.

Herb-Robert: how does it get through the winter?

Hardy to −25 °C.

• Autumn seedlings and young plants overwinter as small green or red rosettes, visible all winter long.
• Old plants that have flowered die after setting seed.
• Hardy; in mild winters it sometimes still flowers in December.

Diseases and pests

• Too many seedlings: Sometimes seeds itself everywhere. Pull the seedlings out young; the roots come away easily.
• Unpleasant smell: When you pull it out, the plant smells strongly. Gloves keep the smell off your hands.
• Rust and mildew: Sometimes spots or white powder on old leaves in late summer. Harmless; the plant is short-lived anyway.

Through the year

• March: Rosettes grow fast. Move seedlings.
• April: First flowers.
• May: Full flower in the shade. Bees and hoverflies.
• June: Flowering. The first ripe beaks shoot out their seeds.
• July: Flowering. The leaves turn red in the sun.
• August: Flowering. Thin out crowded patches.
• September: Sow where it is to grow.
• October: Last flowers; autumn colour.
• December: Green and red rosettes in winter.

Did you know?

• Where the name herb-Robert comes from is uncertain: it may refer to a Saint Robert.
• Geranium comes from the Greek geranos, crane, after the long beak of the fruit; hence the English name crane’s-bill.
• The ripe fruit works like a catapult: the five segments are flung off with a jerk, sometimes several metres away.