Aconitum

( ak - oh - NYE - tum )

At-A-Glance Information

Also referred to as Aconite, Wolfsbane or Monkshood, this genus of herbaceous perennial flowers needs full sun or partial shade and regular water. Take caution when planting this flower in your yard, as all parts are highly poisonous if ingested and can cause skin irritation if touched. These flowers love growing in open meadows, which is their natural habitat, and will bloom in late summer and fall. Flowers are typically blue to purple, but can also be yellow and white. They also enjoy receiving regular moisture and cool temperatures. These are great substitutes for Delphinium in areas with light shade, and can also be grown as a part of cut flower beds; they will look great in fresh or dried arrangements.

Aconitum Species and Varietals

The genus Aconitum (in the family Ranunculaceae) encompasses over 250 species of flowering plants (including some award-winning hybrid varietals), and derives its name from the Greek word 'akon' which means dart, or javelin. It is rumored that the tips of arrows were poisoned with a substance made from Aconite plants for added injurious effect. Common names for Aconite plants include Leopard's Bane, Devil's Helmet, and Blue Rocket. Aconite grows best in USDA hardiness zones 3-8 or Sunset zones A1-A3, 1-9 and 14-24. To find your zone, click here: Zone Map.

Aconitum anthora (Anthora, Yellow Monkshood, Healing Wofsbane)
This species is native to European mountain ranges and northern Asia and produces yellow flowers that bloom in late summertime. The name anthora refers to this plant's use as an antidote to Leopard's Bane poisonings in livestock and humans. USDA zones 3-7.

Aconitum carmichaelii (Aconitum fischeri) (Chinese Wolfsbane, Carmichael's Monkshood)
Native to eastern Asia, this plant gets 2-4 feet tall and wide. This species does well in USDA growing zones 3-7 and forms a densely-foliaged plant with deep purple flowers that bloom in clusters in late summer and fall. Popular varieties include 'Arendsii', 'Kelmscott', 'Baker's Variety' (robust with violet-blue flowers), 'Autumn Indigo' (with 6-inch spikes of indigo-blue blooms), and 'Royal Flush' (with dark red-tinged new foliage).

Aconitum columbianum (Columbian Monkshood, Western Monkshood, Columbia Monkshood)
This wildflower species grows in meadows and moist areas in riparian landscapes and conifer forests in western North America between 2,000-9,500 feet in elevation. Green leaves are deeply divided and flowers can be blue, white, cream, or blushed blue. Best in USDA growing zones 4a-8b.

Aconitum coreanum (Korean Monkhood, Fuzi, Wutou)
This flower grows wild in the mountainous regions of Korea, China, Mongolia, and Russia. Flowers are yellow and sometimes have a purple tinge to them, blooming in summertime. Leaves are deeply divided and green. Individual plants reach up to 1 to 3 feet tall when mature and in bloom.

Aconitum degenii (Branched Monkshood, Paniculate Aconite)
This wildflower species of Monkshood is native to alpine and sub-alpine areas in south and south-eastern Europe. Flower stalks are branched and bloom in late summertime. Habit is a bit spindly. This species does best in USDA growing zones 3-8, and prefers woodland, meadow, or streambank habitats.

Aconitum ferox (Aconitum virorum) (Indian Aconite)
This species is one of the most poisonous plant species in the world, and is native to the eastern Himalayan Mountains in Nepal and India in shrubberies and forest clearings. These plants bloom from August to October in their native range. Flowers are very dark blue-purple. This species does well in USDA growing zones 5-9.

Aconitum henryi (Spark's Variety Monkshood)
This species has glossy dark green leaves and a wildflower-like habit. It is native to China's mountainous scrub landscapes and the flowers are blue to deep violet-blue. Individual plants reach up to between 2 and 6 feet tall when in bloom. Cultivar 'Spark's Variety' is a common garden ornamental that tops out at 4-6 feet tall.

Aconitum lamarckii (Aconitum lycoctonum ssp. neapolitanum) (Northern Wolf's Bane, Yellow Monkshood, Lamarck's Wolfsbane)
This species is native to Europe and is sometimes cultivated in home gardens in temperate zones, prized for its showy, creamy yellow flowers that bloom in summertime. This species is named after Jean Baptiste Lamarck. This species reaches up to 2-5 feet tall and 1-2 feet wide, forming clumps over time.

Aconitum lycoctonum (Wolfsbane, Northern Wolf's Bane)
This species is one of the most commonly found wild species in Europe, and is commonly cultivated in gardens. Individual plants reach up to 3-4 feet tall and 1-2 feet wide. The species was formally discovered in 1727 by Carl Linnaeus in Lapland, Finland. Flowers can be dark violet, white or pale yellow. Best in USDA growing zones 3-9.

Aconitum napellus (Garden Monkshood, Monkshood, Aconite, Venus' Chariot, Wolfsbane)
This species is native to Europe and produces plants with an upright habit to 2-5 feet tall and 1 foot wide. Blue or violet flowers bloom in late summer to fall and are held in spiked clusters. The best growing zones for this species are USDA hardiness zones 3-8. Cultivar 'Ivorine' produces white blooms.

Aconitum noveboracense (Northern Blue Monkshood, Northern Wild Monkshood, New York Monkshood)
This species is considered threatened, due to habitat loss and grows naturally in Iowa, Wisconsin, New York, and Ohio in shaded cliffs and cool streamside areas. Flowers bloom between June and September, and are blue. Individual plants reach up to 1-4 feet tall.

Caring for Aconitum

Please Note: When working with Aconite, it is a best practice to use gloves and wear long sleeves. Also, make sure to take care that you are considering children and pets if you are planting these in your yard; ensure that they have no access to the area. Do not plant Aconite near vegetable gardens or plants that you are harvesting for consumption.

Aconitum, or Monkshood, plants can be grown from seed (either direct-sown or started indoors) or purchased as starts from a reputable nursery. Choose a space in the landscape that is in partial shade to full sun. In warmer climates, give these flowers more shade, and in cooler climates, they can take full sun, especially if soil is kept consistently moist. The best planting time for Aconite is in fall, giving plants time to acclimatize before going dormant over winter. Space plants about 16 inches apart for best coverage and airflow. They appreciate a space that is somewhat sheltered; winds can damage and dry out foliage and knock over flower stalks. Taller varieties of Monkshood benefit from staking. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.5 and 7.0 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. Give your plants a generous amount of water, especially during growth and blooming periods (they will need about an inch of water per week), but ensure that the soil they are in is well-draining, otherwise they will be more likely to have issues like Crown and Root Rot.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Avoid using nitrogen-heavy fertilizers around these plants. Prune to remove spent flower spikes as they fade to clean up the appearance of plants and encourage more blossoms to form. When frost kills these plants to the ground in fall or winter, cut plants back and mulch around the base to protect their sensitive root systems. These flowers will bounce back in springtime with fresh, new growth. Plants will need to be divided every four or five years to prevent root crowding. For instructions on how to divide your plants, see the Propagation section below. A patch of Aconitum plants can be maintained for decades before needing to be replaced; dividing plants can extend their lifespan indefinitely.

Growing Aconitum in Containers
Monkshood plants, especially dwarf species and varieties, can do well in containers. Choose a pot that is at least two inches larger than the nursery pot the plant comes in. If growing Aconitum from seed in a container, choose a pot that is at least 12 inches in diameter. The pot should have excellent drainage holes on the bottom. Fill with a standard potting mix, and apply a layer of mulch to the top of the container to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Place the container in a spot that receives full sun to partial shade. Aconitum grown in containers will need more frequent irrigation than those grown in the ground; as a general rule of thumb, water whenever the top inch of soil feels dry to the touch. Divide plants every few years for best results; for instructions on how to divide a Monkshood plant, see the Propagation section below.

Harvesting Aconitum
Aconitum, or Monkshood, makes a beautiful addition to cut flower arrangements, providing height and distinctive hooded white, blue or purple flowers. Harvest Monkshood just after all flowers have opened on a spike. The best time to harvest is in the early morning or late evening when temperatures are at their coolest. Cut flower stems at their base using sharp, clean shears or snips, remove the lower leaves from the stems, and drop them in a bucket of cool water. The vase life of Monkshood cut flowers is between 7 and 10 days.

Propagation

When you are working with Aconite, take precautions to protect yourself, as this plant is highly poisonous and can cause contact dermatitis; wear personal protective equipment when handling plant parts. The roots of these plants are the most poisonous, so this is especially important if you are propagating by division. Aconite can be propagated by division or by seed. To propagate your Monkshood flowers, follow the instructions below:

Propagating Aconite by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, gloves and other protective wear (to prevent skin contact) and pots (12 inch pots will do, and these are only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every four to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Dawn your protective gear and gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the tuber roots. Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick tuberous section.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided tubers about an inch under the soil surface and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout!

Propagating Aconite by Seed
To propagate your Aconite by seed, you will need gloves and other protective wear (to prevent skin contact), clean, sharp garden shears, fresh soil (any kind will do, though it does need to be well-draining), compost, a plastic bag and paper towel, perlite, and a spray bottle filled with water. Keep in mind that this option will not necessarily produce a clone of the parent plant. If you would like to ensure that you are going to end up with an exact copy of your Aconite, propagate by division (as described above). Also, Aconite grown from seed may take a year or more to sprout, so this way of propagation can require some patience. To grow your Aconite from seed, follow the instructions below:

Dawn your protective gear, cut your dry seed pods off of your existing plant, and open them to reveal the seeds inside. This can be done as soon as the plant's seed pods look like the image below. Store the seeds in a cool, dark place until you are ready to use them. Make sure you harvest and sow a good amount of seeds, as not every one will germinate. It is a good practice to place the seeds in a plastic bag with a damp paper towel and put this bag in your refrigerator for around 3 weeks before sowing. Seeds germinate best when given this little shock of cold.
In late fall a few weeks after the first light frost, seeds can be sown in place. Aconite doesn't do well with transplanting, so this is the best option for successful propagation. Amend the area with about 3 inches of compost and work it into the soil. Place seeds three inches apart and sprinkle a thin layer of soil over the top, then water gently. Maintain constant moisture for about a month, and then thin the seedlings that have sprouted so they are spaced around 16 inches apart. They should be mulched around the bases to keep them cool as the weather warms, and watered once weekly.
If you'd like to sow your seeds indoors first and then move the seedlings outdoors, follow step one and then prepare your pots or trays with well-draining soil amended with perlite. Water your soil to ensure good drainage is occurring. Place seeds in your tray, or spaced about 3 inches apart in a pot (or pots) and cover them with a thin layer of more soil. Locate your tray(s) or pot(s) in a shaded indoor location that receives very indirect light and where temperatures will stay between 55 and 60 degrees Fahrenheit.
Water your seeds with a spray bottle, and continue to keep the top of the soil moist for about a month. Seeds should be starting to germinate and sprout at this time. Decrease watering at this time, allowing the top quarter inch of soil to dry out before adding more water.
After the last frost of springtime has passed, transplant your seedlings into the garden in an area amended with about 3 inches of compost. Space them 16 inches apart for best coverage and performance. Add a little mulch around the bases to keep the soil cool as the weather warms, and ensure they receive water once weekly.