A 285g jar of artichoke hearts costs around £3 in the supermarket. Branded a "taste of Italy" and infused in what's described as a "classic marinade for a mild, distinct flavour", the jar contains four servings. I'm not sure how many artichoke hearts fill a jar or constitute a serving (it must be at least one) yet nonetheless I'm still amazed that they can be so cheap and remain economical to grow, process and pack.
Artichoke hearts come from the inside of the large spherical flowers of the globe artichoke, Cynara cardunculus, a member of the thistle family that has been cultivated since the time of the Ancient Greeks. Of Mediterranean origin, they bear no similarity and are no relation to the Jerusalem artichoke (Helianthus tuberosus), a root vegetable whose smoky-flavoured tubers are harvested from autumn through to winter.
The buds of the globe artichoke are edible before they flower. The most desirable bit is the aforementioned heart, the fleshy core just above where the flower joins the stem. It is comparatively small – about the size of the plug in your sink, though not as tasty. That's actually very unfair, as artichoke hearts may not necessarily have a strong, distinctive flavour, but they are good at taking on flavour – hence the use of a classic marinade in the supermarket jar and its place as the vegetable centrepiece of every antipasto.
The heart is surrounded by stringy flesh – the 'choke' – which should be discarded. However, the thorny petals on the outside of the bulb can be eaten. This rather undignified process involves taking the individual leaf scales and, one by one, dipping them in melted butter, hollandaise sauce or such like, before sucking out the juicy flesh from each.
Globe artichokes are big plants by anybody's standard, towering well above most people's head height. They are truly magnificent, primordial plants, blurring the line between the ornamental and edible garden to an unrivalled degree. Large, silvery green, irregularly lobed leaves remain for much of the year, increasing in volume and height throughout spring and into early summer. Around mid-June long stalks begin to appear, topped with golf ball-sized buds. By the time they've reached full height at more than 1.5m, the flowerhead has swollen to the size of a grapefruit. These 'globes' are made up of dozens of bracts, which take on a purple hue as they mature. The blooms, when they appear, are an inflorescence, a cluster of many small almost iridescent, purple flowers. Once you've reached this stage, the artichoke is no longer edible.
A relative of the ornamental herbaceous perennial known as cardoon (Cynara cardunculus), globe artichokes are (as in my own garden) often deployed solely as ornamentals. One of few drawbacks is the propensity to shed leaves, which break and lie horizontal. They're said not to be fully hardy but mine survived the winter of 2010/11. They can also cowp in a strong wind but prefer an open, sunny site to maximise height.
Most varieties have similar flavour, though the look of the globe may differ. ‘Green Globe' is a common variety with large heads and fewer spikey scales, while ‘Purple Globe' is hardier though doesn't score as highly in the flavour ratings. ‘Vert de Laon' is widely available and ticks all boxes; 'Camus de Bretagne' is the aficionados' artichoke but is more susceptible to frost.