Perennials

Aconitum hemsleyanum

Climbing Monkshood

RanunculaceaeCentral China

At a Glance

TypeVine
HabitClimbing
FoliageDeciduous
Height6–10 feet (1.8–3 m)
Width18–36 inches (45–90 cm)
Maturity2 years

Growing Zones

USDA Hardiness Zones

5 - 8
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Deer Resistant
Maintenancemoderate

Overview

Aconitum hemsleyanum is an herbaceous perennial vine reaching 6–10 feet (1.8–3 m) in length, twining and scrambling through supporting shrubs, perennials, or structures. It is the only commonly cultivated climbing species of Aconitum, distinguished from all other garden monkshoods by its scrambling rather than self-supporting habit. Leaves are palmately divided, 3–5 inches (7.5–13 cm) wide, with five deeply lobed and sharply serrated segments, medium to dark green. Flowers are deep blue-violet to indigo with the characteristic arched hood (galea) of the genus Aconitum, produced in open branched racemes at stem tips and leaf axils from August through September. The twining stems require support — other robust shrubs, perennial clumps, or a trellis. Without support, stems sprawl and trail at ground level. Native to central China. All parts contain aconitine alkaloids and are highly toxic to humans, pets, and livestock.

Native Range

Aconitum hemsleyanum is native to central China, occurring in moist mountain forests and forest margins at elevations of 5,000–10,000 feet (1,500–3,000 m), where it climbs through surrounding vegetation in cool, humid conditions. Named for William Botting Hemsley, the British botanist who documented many Chinese plant species in the late nineteenth century.

Suggested Uses

Planted at the base of robust shrubs, large perennial clumps, or trellises at 18–24 inch (45–60 cm) spacing, where the scrambling stems can be supported. The deep blue-violet August–September flowers extend the shade border into late summer and are produced at eye level when climbing through 4–6 foot (1.2–1.8 m) shrubs. Suited to woodland gardens and shaded mixed borders in zones 5–8. Not suited to open, unsupported positions; dry soils; or gardens accessible to unsupervised children or grazing animals.

How to Identify

Aconitum hemsleyanum is immediately distinguished from other *Aconitum* species by its twining, climbing habit — the only species in common cultivation with this growth form. The deeply divided palmate leaves, 3–5 inches (7.5–13 cm) wide, and the characteristic deep blue-violet hooded flowers (galea) confirm genus identification. The scrambling stems supported by surrounding plants, combined with August–September bloom and deep indigo-blue flower color, are collectively diagnostic. When not in bloom, the twining stems and palmate leaves are the primary identification features.

Appearance

Size & Dimensions

Height6' - 10'
Width/Spread1'6" - 3'

Reaches mature size in approximately 2 years

Colors

Flower Colors

blue
violet

Foliage Colors

dark green
green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~6 weeks
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SummerFall
Deep blue-violet to indigo hooded flowers are produced in open branched racemes at stem tips and leaf axils from August through September, lasting 5–7 weeks. Individual flowers are 1–1.25 inches (2.5–3 cm) long. Racemes open progressively.

Detailed Descriptions

Flower Description

deep blue-violet to indigo

Foliage Description

medium to dark green

Growing Conditions

Sun Requirements

Partial Shade
Full Shade
Requires 2-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.0(Neutral)
357912
Soil Types
loamclay
Drainage
moist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2–3 years

Care & Maintenance

Care Guide

Plant in moist, well-drained, humus-rich soil with a pH of 5.5–7.0 in partial shade. Provide a support structure — robust shrubs, a trellis, or a perennial clump — as stems cannot self-support. Water consistently, weekly during dry periods; does not tolerate drying out. Afternoon shade is beneficial where summer temperatures exceed 75°F (24°C). Performs in zones 5–8. Stems die back to the crown each winter; the climbing stems regrow from the base each spring. All parts are highly toxic — wear gloves when handling.

Pruning

Cut stems to the ground in late fall after frost. Remove dead stems and disentangle from support plants in early spring before new growth emerges. No division is required for many years on established plants. Wear gloves — all parts contain aconitine alkaloids.

Pruning Schedule

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fall

Maintenance Level

moderate

⚠️ Toxicity Warning

Toxic to pets and humans