Aconite, Monkshood, Monk's Coule, Helmet Flower, Cat's Tail
Aconitum napellus

Family: Ranunculaceae (ra-nun-kew-LAY-see-ee) (Info)
Genus: Aconitum (a-kon-EYE-tum) (Info)
Species: napellus (nap-ELL-us) (Info)

Category:

Perennials

Height:

36-48 in. (90-120 cm)

Spacing:

15-18 in. (38-45 cm)

Hardiness:

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Light Shade

Danger:

All parts of plant are poisonous if ingested

Bloom Color:

Blue-Violet

Bloom Time:

Mid Summer

Late Summer/Early Fall

Foliage:

Herbaceous

Blue-Green

Smooth-Textured

Other details:

Requires consistently moist soil; do not let dry out between waterings

Soil pH requirements:

4.6 to 5.0 (highly acidic)

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

Patent Information:

Non-patented

Propagation Methods:

By dividing the rootball

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; stratify if sowing indoors

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds

Regional

This plant has been said to grow in the following regions:

,

Juneau, Alaska

Seward, Alaska

Brookfield, Connecticut

Old Lyme, Connecticut

Lewes, Delaware

Hinsdale, Illinois

Machesney Park, Illinois

Washington, Illinois

Westchester, Illinois

Gorham, Maine

Gaithersburg, Maryland

Jamaica Plain, Massachusetts

Marlborough, Massachusetts

Revere, Massachusetts

Ann Arbor, Michigan

Bridgewater, Michigan

Howell, Michigan

White Lake, Michigan

Gorham, New Hampshire

Jamesburg, New Jersey

Bloomingburg, New York

West Kill, New York

Cleveland, Ohio

Columbus, Ohio

Reynoldsburg, Ohio

Springboro, Ohio

Portland, Oregon (2 reports)

Walterville, Oregon

Bethlehem, Pennsylvania

Coopersburg, Pennsylvania

Rapid City, South Dakota

Leesburg, Virginia

Lexington, Virginia

Olympia, Washington

Seattle, Washington

Green Bay, Wisconsin

Madison, Wisconsin

Watertown, Wisconsin

show all

Gardeners' Notes:

7
positives
3
neutrals
0
negatives
RatingContent
Positive

On Oct 26, 2009, avjudge from Somerville, MA wrote:

I love these in the very neglected garden at my parents' house in northern NH (zone 4) - they keep thriving and blooming with no care (none at all for the 3 years since my mom died, little before that). They bloom late when everything else is looking ratty, with a glorious deep blue.

I transplanted some to my former Connecticut home and found that the deer ate each bud as it opened so no flowers. And no dead deer that I ever saw. (And believe me, there are times I would have welcomed it.)

Positive

On Oct 27, 2008, lch6879 from Portland, OR wrote:

I love this plant. I have one that is now about 5 feet high and blooms in the fall. I also have one that blooms in the summer. I respect that they are very poisonness, so I handle with gloves carefully.

Positive

On Oct 11, 2007, ifonly from Brookfield, CT wrote:

Mine are growing in full sun, in a dry part of the garden. Not as bushy as the one in pix said to be growing in Seward Alaska, sad to say, but a beautiful deep purple blue. Nice combined with Hot Lips chelone and Becky shasta daisies.

Positive

On Jan 15, 2006, Gabrielle from (Zone 5a) wrote:

I love this plant. It grows under a maple tree where very little will survive, and it blooms so late in the year (October-November in my garden) when most blooms are finished. The blooms are so fascinating, too!

I have read that it is hardy in zones 3-9. Also known as Wolfbane. In sunnier areas it needs a lot of water.

Positive

On Jan 7, 2006, KatieLovesDogs from Indianapolis, IN wrote:

Monkshood adds a nice blue color to a fall shade garden.

Neutral

On Apr 2, 2005, SalmonMe from Springboro, OH (Zone 6a) wrote:

When handling monkshood, take care to keep plant away from open wounds and be certain to wash hands thoroughly. Wash immediately after cutting back this plant. A second flowering can be encouraged by deadheading to a lateral bud, but second flowering will produce smaller flowers. After second flowering, cut down to basal growth. Use caution when placing this plant in the garden as it is highly toxic.

Neutral

On Feb 28, 2003, Aultaine wrote:

Could anyone tell me where to buy wolfbane seeds?

Positive

On Oct 20, 2002, mingsmimi from Sharpsville, PA (Zone 5a) wrote:

Mine bloomed October 13. Makes a lovely cut flower! I got a good 3 arrangements worth on one plant its first year blooming.

Positive

On Sep 12, 2002, megabrams from Indianapolis, IN wrote:

Regarding the seeds: Seeds must be cold treated first. Place in a fridge for 6 weeks. Seeds have irregular germination times. Germ. can take between 5 and 270 days. Germ. temperature should be 55-60 deg. Plant seeds 1/16" deep in well drained soil.

Neutral

On Nov 3, 2000, jody from MD &, VA (Zone 7b) wrote:

There are around 100 species in this genus, the most common being napellus. Best cultivated in rich, moist soil and in part shade if summers are hot and dry. They grow to 3' to 6' tall depending on species. The leaves resemble Delphinium leaves. The flowers have the appearance of a monks hood, hence the common name. All parts of this plant are poisonous, this is where the common name of wolfsbane comes from. They used to use it as a poison on wolves. The flowers are deep blue to purple although it is possible (but sometimes difficult) to find species that come in white, pink, and yellow. Most species are hardy zones 4-9.