Cardoon, Cynara cardunculus (Asteraceae)
A not for the faint-hearted vegetable garden: Cardoon with Comfrey (Symphytum officinale) and Fennel (Foeniculum vulgare)
In recent years the vegetable garden has become both a productive and ornamental feature of many gardens. In some cases it has made the switch from backyard to front garden, possibly at the expense of many flower displays of Petunias and Phlox. Driving around at this time of year I see tee-pees of climbing beans and the tasseled flowers of sweet corn peeping over the front fence of many homes.
For those looking for a dramatic foliage plant, architectural even, with huge flowers, it is hard to go past the Cardoon. Related both to the globe artichoke and the scotch thistle, it has more in common with the latter as it is a spiny and prickly customer. It also can be a bit weedy. When the purple flowers have finished, hundreds of fluffy wind borne seeds are sent into space and hence it has weed status in many parts of the world. It was even noted as such back in 1845 by Charles Darwin writing in his Journal of the Voyage of the H.M.S Beagle for in the chapter Banda Oriental (del Uruguay) he noted 'very many, probably several hundred, square miles are covered by one mass of these prickly plants and are impenetrable by man or beast. Over the undulating plains where these great beds occur nothing else can now live.' This sounds very similar to the problem faced in Australia by the 'prickly pear' (Opuntia sp) menace of the late 19th and early 20th Century.
Cardoon is weedy both in central Victoria and around Adelaide. However it is 'harvested' and used as a forage plant by many who are partial to the delicate flavour of the peeled and blanched stems and flower bases. Both of the related familiar garden weeds, the spear thistle (Cirsium vulgare) and the true Scotch thistle (Onopordum acanthium) can be used in this way, though thick gloves and possibly a suit of armour are recommended when handling them.