Siebold's hosta

Sun

Partial to full shade; gentle morning sun is suitable where soil stays moist. Avoid hot afternoon sun, especially in warmer regions.

Water

Keep evenly moist during growth, watering deeply during dry spells. Avoid waterlogged soil, particularly in winter.

Soil

Humus-rich, moisture-retentive but well-drained soil; tolerates acidic, neutral and mildly alkaline conditions.

Height

2-3 ft (0.6-0.9 m), with flower stems sometimes reaching 4 ft (1.2 m)

Spread

3-4 ft (0.9-1.2 m)

Flowers

Early to midsummer; white to very pale lilac, funnel-shaped flowers held above the leaves.

Foliage

Large, heart-shaped, thick leaves with deeply impressed veins and a puckered surface. A waxy coating gives them a blue-grey colour, which can become greener as the season progresses.

Growth

Slow to moderate; allow several years for a substantial clump.

Care needed

Low

• Water at soil level during dry weather, soaking the root zone rather than sprinkling lightly.
• Apply a layer of compost or leaf mould in spring, keeping it clear of emerging shoots.
• Feed lightly with a balanced fertiliser in spring if growth is weak or the soil is poor.
• Protect emerging shoots from slugs and snails before leaves unfurl.
• Divide only when you want more plants or the clump has outgrown its space; frequent division is unnecessary.

Pruning. Cut spent flower stems down to the base unless you want seed. Remove leaves after they yellow and collapse in autumn, taking away damaged or diseased material.

Early spring

Check for emerging shoots and begin slug and snail control.

Spring

Plant or divide clumps as growth starts, then water thoroughly.

Mid-spring

Mulch with compost or leaf mould and feed lightly if needed.

Summer

Water deeply in dry spells and watch for scorched leaf edges.

After flowering

Remove faded flower stems unless saving seed.

Late autumn

Clear collapsed foliage and check that winter water drains freely.

• Plant in generous groups beneath deciduous trees where roots have access to moisture.
• Pair with ferns and fine-leaved sedges to contrast their textures with its broad leaves.
• Use as a bold foliage anchor along a shaded path, allowing room for the mature spread.
• Grow in a large shaded container with reliable watering and unobstructed drainage.

Garden styles it suits: Woodland, Japanese, English country, Blues and silvers, Green on green and Pacific Northwest woodland.

Plant it with: Japanese painted fern, Astilbe, Siberian bugloss, Japanese forest grass, Barrenwort and Solomon's seal.

Wildlife: Flowers provide nectar for bees and may attract hummingbirds in North America. Leaves are eaten by deer, slugs and snails.

• Slugs and snails chew holes, especially in young leaves: inspect at dusk, remove hiding places and use labelled iron-phosphate bait where needed.
• Deer can strip the foliage: use effective fencing where browsing is frequent; repellents need repeated application.
• Hosta virus X can cause unusual mottling, puckering or colour bleeding along veins: remove and dispose of infected plants, do not divide them, and disinfect cutting tools between plants.
• Drought and hot sun cause brown leaf edges and loss of blue colour: provide afternoon shade, mulch and water deeply; avoid compensating with permanently soggy soil.

All parts contain saponins and are toxic if eaten by cats, dogs or horses, usually causing vomiting, diarrhoea or abdominal discomfort; dogs and cats may also become depressed. Seek veterinary advice after ingestion. It is not generally considered toxic to people, but do not assume an unidentified garden plant is edible.

• Blue plantain lily (Hosta ventricosa)

  Usually has glossy green rather than waxy blue-grey leaves, with more distinctly purple, bell-shaped flowers.

• Small-leaved plantain lily (Hosta sieboldii)

  A much smaller plant with narrow leaves, often white-edged in cultivated forms, rather than the large, broad, puckered leaves of Siebold's hosta.

Hosta honours Austrian botanist Nicolaus Thomas Host, while sieboldiana honours Philipp Franz von Siebold, a physician and plant collector who worked in Japan.

Propagation. Divide established clumps in early spring as shoots emerge, keeping roots and several growing points on each section. Seed can be sown fresh, but seedlings vary and will not reliably reproduce a named cultivar.

Accepted botanical name

Hosta sieboldiana

Native range

Japan.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.