Friday, June 19, 2015


The Rev. Dana Prom Smith, S.T.D., Ph.D. (6/13/2015)


          Springtime is weed time.  First, the dandelions appear here and there with their bright, cheerfully yellow flowers.  Some gardeners welcome them, finding them medicinally and culinarily useful.  Others despise them, digging them out, root, flower, and petal, no easy task with tap roots burrowing deep in the soil.


          While attitudes about dandelions are ambivalent and even ambiguous, for some weeds there is unanimous disdain.  An unwelcome plant, weeds generally are fast growing, ingenious, invasive, and supernaturally resourceful.


When the Romans conquered England in 41 A.D., they brought with them the scotch thistle (Onopordium acanthium) which originated in lands around the Mediterranean.  It eventually hopped over Hadrian’s Wall, the Roman barrier defending Roman England from the Scots to the north.


The scotch thistle flourished in Scotland where it proved itself a defense against Viking invaders.  In a nighttime sneak attack upon Scotland, the Norse, unshod for silence, stumbled into a thicket of scotch thistles.  Their cries of pain awakened the inhabitants who drove them back into the sea.  It was imported into the United States as an ornamental shrub because its beautiful flowers.


Now it has become an invasive, noxious weed.   The Latin phrase Nemo Me Impune Lacessit  (No One Injuries Me Unpunished) is on the national emblem of Scotland along with the scotch thistle.  By the way, after pulling them, put them in a plastic garden bag and dispatching them to the county dump.  Pull them wearing full body armor.


Another oddity is that it is a cousin to the artichoke (Cynara scolymus), both being members of the tribe Cynareae which takes its name from the Greek word for dog, their bracts looking like the teeth of a snarling dog.   It’s a delightful vegetable with anti-oxidant and anti-cholesterol benefits.  Artichokes can be grown in Flagstaff just as can scotch thistles; however, while the artichokes grown here are beautiful, they aren’t nearly as tasty as those grown in Castroville, California.


Another member of the tribe Cynareae is the Centaurae diffusa, commonly called the diffuse knapweed which in the fall and winter turns into the tumbleweed.  It, too, has snarling dog’s teeth.  The word cynic comes from the Latin word for dog, cynicus.  Cynics are toxic, baring their ideological teeth, claiming that everything is rotten save themselves.


The diffuse knapweed is a true cynic because it poisons the soil around it so that nothing else can grow save itself, eliminating any competition.  It’s called allelopathy which means that a plant can release chemicals that inhibit the development and growth of neighboring plants.  Just as cynics poison a social environment, so do diffuse knapweeds poison a horticultural environment, eliminating their competition by toxicity.


One plant can produce 18,000 seeds which are spread by the wind as its tumbles over the land.  A genuinely ugly plant, it is scraggly, prickly, and unappealing, with no known benefits.


When destroying it, it should be rooted out before it goes to seed, plant and roots, put into plastic garbage bags, and dispatched to the garbage can.


Then there is cheat grass (Bromus tectorum), a truly despicable and aptly named form of vegetation.  With its lateral roots it sucks up moisture from the soil, cheating other vegetation of moisture.  Capable of displacing every thing else, especially native vegetation, it’s easily combustible, making it a fire danger.  A seedy profligate, it grows almost anywhere in the most miserable of soils, especially soils that have been disturbed.  The best thing to do is pull it as soon as it is seen.  A native of Asia Minor, it was imported with bales of alfalfa and has no known adversaries.


The scotch thistle, diffuse knapweed, and cheat grass will arrive this spring.  Show them no mercy.

Copyright © Dana Prom Smith 2015

Dana Prom Smith and Freddi Steele edit Gardening Ectetera. His email address is and he blogs att