Aconitum carmichaelii 'Arendsii'
Overview
Uses: Shaded borders, woodland gardens, cottage gardens, late-season perennial beds
Benefits: Tall architectural flower spikes, rich blue-purple color, strong late-season interest, deer resistance
USDA Hardiness Zones: 3–7
Sun: Full Sun to Partial Shade
Life Cycle: Hardy Perennial
Growth Habit: Upright, Clumping — sturdy stems with vertical flower spikes.
Bloom Color: Deep Blue to Purple
Mature Height: 36–48"
Mature Width: 18–24"
Bloom Season: Late Summer to Early Fall
Growth Rate: Moderate
Summary
'Arendsii' monkshood is a plant of striking contrasts—valued equally for its dramatic beauty and its well-known toxicity.
Tall spires of deep blue-purple, helmet-shaped blooms rise above clean green foliage in late summer, bringing bold vertical structure just as many other garden plants begin to fade. The distinctive hooded flowers give the plant its common name, monkshood, and create strong architectural presence in partially shaded borders and woodland-inspired plantings.
Historically associated with its poisonous properties, monkshood has long carried a reputation as both ornamental treasure and dangerous plant. In the modern garden, it is grown strictly for its visual impact and late-season color, with appropriate care taken during handling and placement.
Care
Monkshood Care
Plant in moist, well-drained soil enriched with organic matter. Partial shade is preferred in warmer regions, while full sun is tolerated in cooler climates if soil remains consistently moist.
Water regularly during establishment and during extended dry periods. Avoid allowing soil to dry out completely.
Apply a light feeding of slow release fertilizer in early spring if desired.
Cut back spent flower stalks after blooming. Divide clumps in early spring every few years to maintain vigor.
Wear gloves when handling plants or dividing roots.
Plants hardy in the ground may require winter protection when grown in containers in colder zones.
Size
What Size is Monkshood for Sale Online?
Plants ship in greenhouse-grade grow pots and are well-rooted at the time of shipment. For current pot dimensions or seasonal sizing details, please contact us.
How Large Does Monkshood Grow?
At maturity, plants typically reach 36–48 inches tall and 18–24 inches wide, forming upright clumps with prominent flowering spikes.
Additional Information
What are some common names for this plant?
Aconitum carmichaelii 'Arendsii' is commonly known as monkshood, wolfsbane, or aconite.
Is monkshood poisonous?
Yes. All parts of Aconitum are highly toxic if ingested, and sap may cause skin irritation in some individuals. Gloves should be worn when handling the plant, and it should be placed away from areas accessible to children or pets.
Does monkshood attract pollinators?
The late-season flowers attract bees and other beneficial insects and complement plantings of Perennials and Deer-Resistant Perennials and Grasses.
Is monkshood deer resistant?
Due to its toxicity, monkshood is generally avoided by deer and is often included in deer-resistant garden designs.
