White dead-nettle

How to recognise it

Habit

Perennial with creeping rhizomes and upright, usually unbranched stems of 20–50 cm; forms patches.

Leaf

Opposite, heart-shaped to oval, 3–8 cm, coarsely toothed and hairy, but without stinging hairs.

Flower

White to creamy white, 2–2.5 cm, with a hood-shaped upper lip and a lower lip; in whorls in the leaf axils.

Stem

Square, hollow and slightly hairy.

Fruit/Seed

Four small nutlets per flower, at the bottom of the calyx. Ants carry the seeds off for their nutritious appendage.

Confusion with

Common nettle has stinging hairs and green, drooping catkins. Yellow archangel has yellow flowers and grows in woods. Without flowers: a dead-nettle does not sting.

Flowering: April–October · Pruning: March and July

Why grow it?

• Flowers from April into October, providing nectar and pollen for months.
• A true bumblebee plant: garden bumblebees and other long-tongued bumblebees reach the nectar deep in the flowers.
• Early food for bumblebee queens and the hairy-footed flower bee in April.
• Forms dense patches along hedges and wooded banks, giving shelter to small animals.
• The young leaves were once eaten as a vegetable, and children sucked the sweet nectar from the flowers.

White dead-nettle: where does it grow best?

• In the wild: hedges, woodland edges, road verges, field margins, ditch banks, rough ground and farmyards, on fertile soil.
• In the garden: sun to partial shade, along a hedge, at the edge under trees or in a wild corner.
• Moist, humus-rich and fertile soil; loam and clay are ideal.
• It does not tolerate frequent mowing: a spot you cut only once or twice a year is perfect.

Goes well with

• Common comfrey: Another bumblebee plant, with purple or white bells, for the same fertile soil.
• Red campion: Pink flowers in May–June, lovely among the white.
• Ground-ivy: Blue-violet flowers in spring as a creeping lower layer.
• Tufted vetch: Purple clusters that climb between the stems, also loved by bumblebees.

White dead-nettle: when and how to plant it?

1. Buy plants from a native plant nursery or ask for a piece of rhizome from someone who already has it. Never dig plants up from the wild.
2. Plant in March–April or September–October, 30–40 cm apart.
3. Sowing is possible too: sow in September–October outdoors or in pots left outside over winter; the cold helps germination.
4. Water well when planting and keep the soil moist for the first few weeks.
5. Choose a spot where it may spread: the rhizomes creep slowly outwards.

Care

Water

Only after planting and during long dry spells.

Feeding

Not needed; on fertile soil it already grows well. On poor soil a little compost is enough.

Mowing

Mow or cut once or twice a year: after the first flush in July, so it flowers again, and the old stems in March.

Spreading

The rhizomes spread slowly. In spring, cut off the edges with a spade if it goes too far.

Letting it seed

Let the last flowers set seed in autumn: ants spread it.

Tip: Cut white dead-nettle back to 10 cm in July: after a few weeks it looks fresh again and flowers on into October, when bumblebees are still looking for food.

Pruning and mowing

Pruning months: March and July.

When: Cut back after the first flush in July; clear the old stems in March.

How:

• In July, cut the faded stems back to 10 cm above the ground: within a few weeks a new flush of flowers follows.
• In autumn, leave the stems standing: they give shelter to insects.
• In March, remove the old, dead stems before the new shoots come up.
• Never cut everything at once during flowering: always leave some in flower for the bumblebees.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March or September–October, cut off a piece of the clump with rhizomes and replant it elsewhere.

Seed

Sow ripe seed in September–October in pots left outside over winter; it germinates in spring.

White dead-nettle: how does it get through the winter?

Hardy to −30 °C.

• The stems die back in autumn; the rhizomes survive winter.
• In mild winters a few green shoots often remain, and it sometimes flowers as early as March.
• Fully hardy.
• The old stems and the leaves at the base shelter small insects.

Diseases and pests

• Spreading: On rich soil it can smother lower plants. Cut off the edges in spring.
• Powdery mildew: White powder on the leaves in dry summers. Cutting back and watering helps.
• Holes in the flowers: Small holes at the base of the flower tube are made by short-tongued bumblebees that ‘steal’ the nectar. Harmless.
• Nettles mixed in: It often grows together with nettles. Pull those out wearing gloves, or leave a few for the butterflies.

Through the year

• March: New shoots. Clear old stems. Plant or divide.
• April: First flowers. Bumblebee queens and flower bees visit.
• May: Full flower.
• June: Flowering. Garden bumblebees crawl in and out of the flowers.
• July: After the first flush, cut back to 10 cm.
• August: New shoots and a second flush of flowers.
• September: Flowering. Sow or divide.
• October: Last flowers. Leave the stems standing.
• December: Rest. The rhizomes are safe in the soil.

Did you know?

• Dead-nettle means a nettle that is ‘dead’, without sting: it looks like a stinging nettle but does not sting.
• Short-tongued bumblebees, such as the buff-tailed bumblebee, sometimes bite a hole at the base of the flower tube to steal the nectar without pollinating the flower.
• The seeds carry a nutritious appendage, for which ants drag them to their nest: this is how the plant spreads.