Common Name: monkshood
Type: Herbaceous perennial
Family: Ranunculaceae
Zone: 3 to 7
Height: 2.00 to 4.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: July to August
Bloom Description: Violet-blue
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Showy
Tolerate: Deer
Culture
Best grown in moist, organically rich, well-drained soils in full sun to part shade. Soils must not be allowed to dry out, but need sufficient drainage to prevent wet conditions from developing. Best in full sun in cool summer climates. Appreciates some afternoon shade in the St. Louis area. Needs cool nights below 70 degrees F. to grow well, and, like the related delphiniums, will often struggle in hot St. Louis summers. Cut back stems after flowering to encourage an additional late season bloom. Although plants may be propagated by division, they are often slow to establish and are probably best left undisturbed once planted.
Noteworthy Characteristics
Aconitum is a genus of about 100 species of biennials and perennials from the Northern Hemisphere. All parts of the plant (especially roots and seeds) are poisonous. The drug aconite was once made from the roots of monkshood (usually from A. napellus) and prescribed as a cardiac and respiratory sedative.
Genus name is the Latin name from the Greek akoniton used for these poisonous herbs.
The upper sepal of each flower develops into a large, helmet-like structure that somewhat resembles the hood worn by medieval monks, hence the common names of monkshood and helmet flower.
‘Spark’s Variety’ is a monkshood cultivar that features hooded, dark violet blue flowers in dense terminal racemes (to 8” long) atop rigid, leafy stems typically growing 2-4’ tall. This is an erect, tuberous-rooted perennial with dark green leaves are deeply divided into 5-7 lobes.
Problems
No serious insect or disease problems. Crown rot, powdery mildew and verticillium wilt are occasional problems. Taller stems may need support, particularly if plants are grown in exposed areas. WEAR GLOVES WHEN WORKING WITH THIS PLANT. Avoid skin or oral contact with plant juices, and be particularly careful to cover up any open cuts or skin abrasions prior to entering garden areas.
Uses
In the St. Louis area, this plant needs consistently moist soils and may be best grown in moist woodland areas, along streams or ponds, or on the periphery of bog or water gardens. Will grow in borders as long as the soil moisture requirements can be met. Because of the poisonous properties of the plant, it probably should not be grown in areas where small children might come in contact with it or in areas contiguous to vegetable gardens where tubers are growing.