Spotted dead-nettle

Spotted dead-nettle: how do you recognise it?

Habit

Creeping and ascending stems 15–20 cm tall that root at the nodes and form mats up to 60 cm wide.

Leaves

Heart-shaped, scalloped and slightly hairy, up to 5 cm long; green with a silvery-white blotch or stripe in the centre, in some cultivars almost entirely silver or yellow.

Flowers

Lipped flowers of 2–3 cm in whorls at the top of the stems, from April to July.

Colour

Pink to purplish pink, white in some cultivars.

Stems

Square, as in all members of the mint family; stems lying on the ground root by themselves.

Flowering: April–July · Plants: March–May and September–October · Pruning: March and June

Why grow it?

• A long flowering season for shade: from April into July, and often again after cutting back.
• The silver-marked leaves light up dark corners under trees and shrubs.
• Loved by bumblebees, whose long tongues easily reach the nectar.
• A fast, low ground cover that keeps weeds down under shrubs.
• Native and undemanding: any soil from sand to clay will do.

Spotted dead-nettle: where does it grow best?

• Partial shade or shade; in full sun the leaves scorch, especially in silver-leaved cultivars.
• Any soil will do, from sand to clay, acid, neutral or chalky.
• Average soil that is neither bone dry nor waterlogged.
• Plant 6–8 plants per m², 35–40 cm apart, for example under shrubs.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.2 m tall, 0.6 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Hosta: Large, plain leaves beside the fine, spotted foliage.
• Ferns: Green, airy fronds above the silvery mat.
• Hellebore: Evergreen leaves and winter flowers in the same partial shade.
• Hydrangea: The dead-nettle covers the soil beneath the shrub.
• Snowdrop: Flowers early, before the dead-nettle really gets going.

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

Plant in March–May and September–October.

1. Plant in March–May or in September–October, when the soil is neither frozen nor too wet.
2. Loosen the soil and mix in some compost or leaf mould.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. Space 6–8 plants per m², 35–40 cm apart.
5. Water in well straight away and keep the soil moist for the first few weeks.
6. A thin mulch of leaf mould helps the young plants get going.

Care

Watering

During long dry spells, especially in the first year and under trees with many roots.

Feeding

A little compost in spring is enough; too much fertiliser gives long, floppy stems.

Cutting back

Cut the plant back hard after the first flush: you get fresh leaves and often a second flowering.

Spread

If it gets too exuberant, pull up stems or slice off a piece with a spade.

Tidying

In March, remove dead stems and leaves damaged by frost.

Tip: Cut back hard after the first flush and water well: within a few weeks you will have fresh, silvery leaves and often a second flowering.

Spotted dead-nettle: when to prune it?

Pruning months: March and June.

When: After the first flush of flowers, in June, cut the plant back hard. In March, clear away dead stems.

How:

• In June, cut the stems back to 5–10 cm above the ground, or shear the plant with hedge shears.
• Then water and add some compost: within a few weeks fresh leaves appear, often followed by a second flowering.
• In March, remove dead, bare stems.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Layers

Stems lying on the ground often root by themselves: cut them off in spring or September and replant them.

Division

In spring or September, split the clumps with a spade and replant the pieces.

Cuttings

In summer: tip cuttings of 5–8 cm root easily in moist cutting compost in a shady spot.

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

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection is needed.
• In mild winters some leaves remain; in severe winters it dies back above ground and regrows in spring.
• In pots and troughs it simply overwinters outdoors.

Diseases and pests

• Powdery mildew: White powder on the leaves in dry summers. Remove affected leaves, water, and if necessary cut the whole plant back.
• Scorched leaves: Brown patches and edges in full sun, especially in silver-leaved cultivars. Move the plant to more shade.
• Bare centre: Older mats open up and go bare. Cut back after flowering or replant young pieces.
• Too vigorous: In a good spot it can smother smaller neighbours. Pull up stems or slice off pieces.

Through the year

• March: Clear away dead stems. Apply compost. Planting.
• April: Flowering begins. Planting.
• May: Full flower. Planting.
• June: Cut back hard after the first flush. Water and apply compost.
• July: Fresh leaves and often a second flowering. Take cuttings.
• August: Water during dry spells.
• September: Planting and dividing.
• October: Planting.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Dead-nettles get their name because they look like stinging nettles but do not sting.
• It is not related to the stinging nettle, but to mint, sage and thyme.
• The flowers have a long tube: mainly long-tongued bumblebees can reach the nectar.