Solomon's seal

Solomon's seal: how do you recognise it?

Habit

Gracefully arching, unbranched stems about 70 cm long from a creeping rhizome; the group slowly widens.

Leaves

Oval to elliptic, 5–15 cm, in two rows along the stem; fresh green with distinct veins, yellow in autumn.

Flower

Tubular, 1–2 cm long, in clusters of two to five beneath the stem, in May and June.

Colour

White with green tips.

Fruit

Round, blue-black berries in late summer; poisonous.

Rhizome

Fleshy and white, creeping horizontally just below the surface, with round scars left by old stems.

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

Why grow it?

• One of the loveliest plants for partial and full shade beneath trees and shrubs.
• Elegant, arching stems that give structure in spring.
• Native; bumblebees visit the dangling flowers.
• The leaves turn buttery yellow in autumn.
• Spreads slowly into a fine group without becoming invasive.

Solomon's seal: where does it grow best?

• Partial to full shade, for example under trees, between shrubs or on the north side of a house.
• Humus-rich soil: sand, loam or clay, acid to chalky.
• Moderately moist; mix leaf mould or compost into poor sandy soil.
• Plant 30–40 cm apart, in small groups for the best effect.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.7 m tall, 0.4 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Ferns: Fine, lacy fronds beside the arching stems, in the same shade.
• Hosta: Large leaves at the base, in the same partial shade.
• Lungwort: Silver-spotted leaves and early flowers at the base.
• Sweet woodruff: A white-flowered native carpet underneath.
• Wood anemone: White stars in early spring, before the Solomon’s seal comes up.

Solomon's seal: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or September–October.
2. Mix leaf mould or well-rotted compost into the soil.
3. Lay the rhizomes horizontally and shallowly, about 5 cm deep, with the buds facing up.
4. Leave 30–40 cm between plants.
5. Firm the soil and water thoroughly.
6. Mulch with leaf mould or fine wood chips.

Care

Watering

In dry spells in the first year; after that only in dry summers, especially under trees.

Mulching

A layer of leaf mould every spring or autumn: it mimics the woodland floor it comes from.

Feeding

Not needed on top of the mulch.

Checking

In June, look under the leaves for grey sawfly larvae and pick them off.

Leave alone

Disturb the clump as little as possible; it gets better every year.

Tip: Plant the rhizomes horizontally and shallowly in humus-rich soil. In June, look under the leaves: grey sawfly larvae can strip the plant bare, so pick them off straight away.

Solomon's seal: when to prune it?

Pruning months: November.

When: In November, when the leaves are yellow or brown, cut the stems down to just above the ground. You can also leave them until spring.

How:

• Cut the dead stems down to just above the ground.
• Leave the leaves between the plants as mulch or put them on the compost heap.
• Remove the berries if young children or pets play in the garden.

Caution: Keep the spade away from the rhizomes: next year’s buds sit just below the surface.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March or in September–October: dig up a piece of rhizome with at least one bud and replant it horizontally and shallowly.

Seed

In autumn, sow seeds cleaned of their flesh in a pot outdoors. Germination is slow, often only after two winters, and seedlings take several years to flower.

Solomon's seal: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection is needed.
• The plant dies back in autumn after a fine yellow autumn colour.
• A winter blanket of fallen leaves is ideal; leave leaves from trees where they fall.

Diseases and pests

• Sawfly: In June, grey larvae with black heads strip the leaves until only the veins remain. Check under the leaves and pick them off; the plant comes back as usual the next year.
• Slugs: They eat the young shoots in April. Pick them off in the evening.
• Scorched leaves: Brown leaf edges from too much sun or drought. Water, or move it to a shadier spot.
• Poor growth: In poor, dry sandy soil it stays small. Mulch every year with leaf mould.

Through the year

• March: Plant and divide. Mulch with leaf mould.
• April: New shoots appear. Watch for slugs.
• May: White, dangling flowers in bloom.
• June: Last flowers. Check under the leaves for sawfly larvae.
• July: Water in long dry spells.
• September: Plant and divide. Blue-black berries.
• October: Plant. Yellow autumn colour.
• November: Cut down dead stems. Mulch with leaf mould.

Edible and useful

Not edible. Solomon’s seal is poisonous in all its parts, especially the blue-black berries, which can tempt children. The young shoots in spring look like asparagus but are not for eating. Also poisonous to dogs and cats. 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.

Did you know?

• The name Solomon’s seal refers to the round scars on the rhizome where old stems once stood: they look like the impression of a seal.
• Most Solomon’s seals sold in garden centres are a hybrid between this species and the scented Solomon’s seal.
• The flowers are pollinated mainly by bumblebees, whose long tongues reach deep into the tubes.