Viper’s bugloss

Viper’s bugloss: how do you recognise it?

Habit

Biennial: a flat rosette in the first year, a stiff, upright flower stem 60–80 cm tall and 30 cm wide in the second.

Leaves

Narrow and lance-shaped, rough and stiffly hairy; the stem is covered in bristly hairs on dark red specks.

Flowers

Funnel-shaped, lopsided flowers 1–2 cm long with protruding stamens, in coiled clusters that slowly unfurl; from June to September.

Colour

Pink buds that open into bright blue to violet-blue flowers with reddish-purple stamens.

Roots

A long, deep taproot, which helps it cope with drought but makes it hard to transplant.

Flowering: June–September · Sowing: April–July

Why grow it?

• One of the best bee plants: honeybees, bumblebees and wild bees visit it all day long.
• Flowers for months, from June to September, with a lovely interplay of pink buds and blue flowers.
• Native and valuable for wildlife, ideal for a wild garden, a wildflower meadow or a gravel garden.
• Grows on poor, dry sandy soil where few other plants thrive, and tolerates drought extremely well.
• Needs no watering, no feeding and no pruning.

Viper’s bugloss: where does it grow best?

• Full sun: in shade it hardly flowers and the stems flop.
• Poor, free-draining sandy or loamy soil, gravelly soil too; acid to chalky. Rich soil gives floppy plants.
• Dry: wet soil makes the rosette rot in winter.
• Ideal in a gravel garden, a dry meadow, along a sunny path or on a bank. Allow about 30 cm per plant.

Light

Sun

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Dry

Size

0.8 m tall, 0.3 m wide

Hardiness

Hardy (to -20 °C)

Goes well with

• Great mullein: Also biennial and loved by bees, with yellow candles in the same dry spot.
• Wild marjoram: Pink flower clusters in summer, another top plant for bees and butterflies.
• Yarrow: White flower heads on dry, poor soil, a calm contrast to the blue.
• Harebell: Delicate blue bells on poor, sandy soil, also native.

Viper’s bugloss: when and how to plant it?

1. Sow in place from April to July: because of its long taproot it does not transplant well.
2. Clear a patch of bare soil and rake it loose; no fertiliser or compost is needed.
3. Scatter the seed thinly and rake it in lightly, about 0.5 cm deep.
4. Keep the soil slightly moist until the seedlings come up, after 2–3 weeks.
5. Thin the seedlings to about 30 cm. Small rosettes can still be moved carefully with a good root ball.

Care

Watering

Not needed, except during germination. Once established, the taproot finds water deep down by itself.

Feeding

Never: in rich soil the stems become floppy and fall over.

Weeding

In the first year, keep the ground around the young rosettes clear of tall weeds.

Spent spikes

Cut off faded stems if you want it to self-seed less; leave a few for new plants.

Gloves

Wear gloves when handling it: the stiff hairs prickle and can irritate the skin.

Tip: Sow in place in spring or summer on dry, sandy soil; the following year it flowers for months. One of the best bee plants. Contains poisonous alkaloids.

Viper’s bugloss: when to prune it?

When: Viper’s bugloss is not pruned. At most, you cut off spent spikes in August or September and clear away the dead plants.

How:

• Cut faded flower stems off at the base to limit self-seeding.
• Leave a few stems if you want it to renew itself in the same spot.
• After it has set seed, pull up the dead plant; it is biennial and will not come back.

Caution: Wear gloves and long sleeves, as the stiff hairs irritate the skin.

Pruning calendar and basic rules

Propagation

Seed

Collect the seed in August–September when it is brown and sow it in place on bare soil from April to July. Plants from seed flower the following year.

Self-seeding

On open, dry ground it self-seeds freely. Leave the rosettes where they fit and weed out the rest while they are small.

Viper’s bugloss: how does it get through the winter?

Hardy to −20 °C.

• The rosettes are hardy, to about −20 °C: in Belgium no protection is needed.
• Wet soil in winter is more dangerous than frost: choose a dry, well-drained spot.
• Do not put mulch or leaves on the rosettes, as they will rot underneath.

Diseases and pests

• Heavy self-seeding: Many seedlings appear on open ground. Cut off spent spikes and weed out seedlings while they are small.
• Rot: In wet or heavy soil the rosette rots away in winter. Only sow on dry, free-draining soil.
• Flopping: On rich, moist soil the stems become long and floppy. Sow on poor soil and do not feed.
• Skin irritation: The stiff hairs prickle and can cause itching or red patches. Wear gloves when weeding and tidying.

Through the year

• March: Last year’s rosettes start growing again. Weed around them.
• April: Sow in place on bare, dry soil.
• May: Sow. The flower stems of second-year plants shoot up.
• June: First flowers. Bees and bumblebees visit. You can still sow.
• July: Full flower. Last sowing time. Thin seedlings to 30 cm.
• August: Flowering. Cut off spent spikes to limit self-seeding.
• September: Last flowers. Collect seed. Clear away dead plants.
• October: Young rosettes are visible. Leave them for next year’s flowers.

Edible and useful

Not edible. Viper’s bugloss contains pyrrolizidine alkaloids in all its parts, which damage the liver, even in small amounts over time. Its rough, hairy leaves and blue flowers recall borage, but never use viper’s bugloss in a salad or tea: borage has broad, oval leaves and nodding, star-shaped flowers with a dark cone of stamens; viper’s bugloss has narrow leaves, a stem covered in dark red spots and funnel-shaped flowers with protruding stamens. Especially dangerous to horses and cattle, in hay too: do not sow it in or next to a field. The stiff hairs can irritate the skin. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The name Echium comes from the Greek ‘echis’, viper: the seeds are said to resemble a snake’s head.
• The colour change from pink bud to blue flower is seen in many plants of the borage family, such as lungwort.
• There is a wild bee, the viper’s bugloss mason bee, that relies almost entirely on viper’s bugloss for its pollen.