Aconitum: Toxic Perennial if Taken Internally
December 16, 2009
Allan in Aconitum, Blue perennials, Garden Design, Monkshood, Perennial Plants, stately perennials, tall plants

Image courtesy of Van Hoorn Nurseries.Aconitum is one of several impressive blue perennials used as background plants in English style gardens. The tall pure blue varieties make nearby pink flowers so vivid-looking that I needed to include Aconitum in my own garden. However, my eagerness for them ebbed when I found these plants at the nursery with a cautionary sign hanging over them that read: this plant is poisonous. Naturally, I chose not to buy. There have always been children playing in or near my flowerbeds. I did not want to deliberately create a scenario that might endanger them.

This stately perennial, also known as Monkshood, is one of the most poisonous of plants. Since ancient times, people have known that it is toxic and have used it as a weapon by coating their spear and arrow heads with its strong poison in order to kill wild animals. Some gardeners believe that this popular garden plant has such a distinctive and unpleasant taste that cases of accidental poisoning are rare, though known. However, all parts of the plant are toxic if eaten and its roots may be fatally mistaken for edible crops if left lying around. Even the abraded skin of a gardener can absorb a dangerous dose of its poison.

Image courtesy of Glenlea GreenhousesSome brave gardeners feel that handling the plant itself is not a problem and there is no reason not to grow it. I argue that if Aconitum were to be planted in ample-sized flowerbeds, such as those on large estates, one might not be so anxious about accidental poisoning. However, in tight urban flowerbeds, where gardeners often collide with their flowers, the possibility of a fatal accident is real.

Here are some of the symptoms of Aconitum poisoning: Burning of lips and mouth, numbness of throat, intense vomiting and diarrhea, muscular weakness and spasms, weak pulse, paralysis of the respiratory system and convulsions. Did you ever expect to read something as gruesome as this in a gardening blog?

Nevertheless, if a reader is determined to grow Aconitum, here is what one needs to know: This tall plant grows stalks that are so strong they do not need staking. There are many varieties of Aconitum, ranging in heights of 18 to 48 inches tall. The color palette includes white, pink and blue. The tall blue varieties are the most desirable because of the purity and intensity of their color. This perennial will grow in full sun or light shade but flowers get floppy with reduced sunlight. Aconitum performs best with a minimum of six hours of full sun every day. This plant blooms in late summer to early fall and is happiest in moist, fertile soil.

As soon as the first flowering flush is over, cut the bloom stalks to the ground to prevent seed development. This will encourage re-blooming later in the summer. Always wear gloves, long sleeved tops and long pants when gardening near this plant. Avoid placing Aconitum close to vegetable gardens or children’s play areas. Depending on the variety selected, this plant will grow in zones 2 to 8. I cannot suggest specific cultivars because I do not grow this species. As breathtaking as this perennial may be, the sounds of children playing touches me deeper.

Article originally appeared on Garden Design, Montreal, Perennial Flower Gardens, Gardening Tips, Gardening Advice, Gardening Book Reviews (http://allanbecker-gardenguru.squarespace.com/).
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