Monkshood with Japanese Forest Grass and Hardy Fuchsia

Portland Landscape Designer loves purple flowers of Monkshood

Portland landscape designer loves purple flowers of Monkshood.  My clients have unique likes and dislikes when it comes to plants.  When they love something specific, like purple flowers, one of my favorites is purple flowered Monkshood.  Other clients are focused on a purpose such as native plants or the lowest of low maintenance plants and not on specific colors.  My job is to find the plant palette that satisfies each client’s needs.

Purple flowers

I love tall columns of  purple flowers in my Portland landscape designs.  I often use them at the back of  planting beds to break up a bare wall or visually soften a fence. It’s an easy care perennial plant with no pest problems. It flowers a long time, provides great contrast with bright green or gold foliage and adds drama to the garden scene.

Aconitum Carmichaelii ‘Tall Blue’ – Monkshood at Joy Creek Nursery

I try to use varieties that don’t flop.  This isn’t as easy as it sounds.  Selection is important.  Shorter varieties are typically less floppy.  Don’t overwater. There is no need to stake the plants if you select the right varieties and water correctly. Staking plants is a hassle and not low maintenance so I don’t use plants that require staking in my designs.  One last thing to consider. Pay careful attention to sun angles since too much south sun without enough overhead sun will cause any columnar plant to lean.  My client Lisa’s monkshood needs staking.  It gets 3 hours and of east sun but a neighbors tree blocks too much west sun and “our” tall monkshood leans and must be staked.  In another garden the same plant gets no east sun at all and full west sun but does not lean one bit.

Here are the Monkshood varieties I use in my Portland landscape designer practice.

Aconitim x napellus ‘Newry Blue’ -Flowers June and July, 4′ tall and an intense purple blue

Aconitum carmichaelii ‘Tall Blue’ – Flowers late August and September at 6′ to 8′

Aconitum Carmichaelii ‘Late Crop’ – Monkshood at Joy Creek

Aconitim x napellus ‘Newry Blue’ – Monkshood

Aconitum carmichaelii  ‘Late Crop’- Flowers into October, is a dark rich purple at 5′ to 6′ tall

Monkshood was used for poisoned arrows

This plant has a checkered past.  In medieval times Monkshood was also called Wolfbane and was the source for poisoned arrows.  Applied to a cut, Monkshood can be deadly and all parts of the plant are toxic.  Yet in modern times it is commonly used by florists and sold by garden centers and nurseries.  In 25 years I have no first hand knowledge of anyone being poisoned by monkshood but I don’t use it in my Portland landscape designs for young families or in parking strips.

How to kill this plant: 

Plant it in full sun and never water it, (or just as bad) water every day in the summer.  Plant in a low place where winter water will soak the roots for days at a time.

Best practice:

Most resources say part shade but I have found they thrive in half day sun to nearly full day sun with a few hours of dappled or light shade. Maybe somewhere they grow in shade but not for me. Deeply irrigate Monkshood in full sun once a week; as years go by this plant with its deep roots will require less frequent watering.  In time most Monkshood will become low water needs.   In too much shade it will flop and will not have as many flowers. Plant in well-draining soil, water established plants deeply once a week.  Don’t fertilize beyond adding a  compost or mulch around the crown twice a year.  Fertilizer may cause the plant to grow too lushly and make the stems flop. Cut it back to the ground in winter or when the leaves have gone yellow.  Learning how to water properly  creates confidence and makes maintaining your landscape less stressful.