Tuesday 10 November 2015

Hairy bittercress

Some plants are just hard to love.

The admission causes me a degree of discomfort, having on numerous occasions made my admiration for weeds a matter of record, but even I find it hard to wax lyrical about hairy bittercress.

“Hairy bastard cress, more like”, a gardening friend of mine once quipped. It’s hard not to sympathise. Whilst the leaves of Cardamine hirsuta – a plant in the brassica family, closely related to mustard and also to garden cress Lepidium sativum – might possess a certain peppery, cress-like taste, it’s difficult to know what it’s good for. You would be bonkers to go out of your way to deliberately grow a crop, not least because surely every plant container in Christendom is sure to become home to at least one or two specimens in any given year.

It’s a nuisance in the nursery – perhaps not to the same degree as the liverworts which blanket the surface of the growing medium, but nonetheless a pretty ubiquitous presence, stealing nutrients and acting as a host for numerous glasshouse pests.

It’s also something of a gremlin in the garden, and you need be in no doubt that you will have hairy bittercress in your garden. Possibly also its cousin, wavy bittercress (Cardamine flexuosa) – very similar in appearance, though the small white flowers have six stamens to the four of its nominally more hirsute relative (the hairs on the leaf margins and axils aren’t particularly noteworthy, in spite of the name). As long as extremes are avoided, bittercress can’t bring itself to be discerning over the pH of the soil, seeming just as at home in acid, neutral or alkaline conditions, and will grow in shade, part shade or sun, in either moist or dry conditions. A hardy annual (C. flexuosa sometimes persisting as a short-lived perennial) it behaves as an ephemeral weed, producing several generations in one growing season, and each plant can produce up to 5,000 seeds.

Not wavy, but downy. Four stamens, so Cardamine hirsuta
Garden designer Chelsea Uribe (@CUgardendesign) pithily summed up generally held opinions on the plant. “That sodding little ruderal. I wish it every ill.” A coloniser of recently disturbed ground, it’s readily identifiable from its rosettes of bright green pinnate foliage with almost circular leaflets at the base, becoming more elongated higher up the plant. Weeding it out isn’t a particularly satisfying experience – although not deep rooted, it’s quite fiddly to handle when it first emerges, and so you might be tempted to allow a clump to grow to a more convenient size for hand-pulling. In which case, you’d best ensure this forward-dated task doesn’t slip your mind, due to the speed at which it will flower and seed.

Common names include lambs cress, spring cress, hoary bittercress, wood cress and flickweed. This last name is particularly descriptive of the manner in which the plant goes about dispersing seed, a trick which anyone who has carelessly reached for a plant which has gone to seed will be only too able to describe. The characteristic long, thin seed pods (known as a siliqua), common to many members of the brassica family, split open when dry, ejecting their contents with some force and scattering seed over a distance of up to six feet, unless prevented from doing so by some intervening object. Such as the face of a surprised gardener.

The ripening seed pods, or silique, ‘overtopping’ the flowers
In Old English herb-lore, bittercress is known as Stune, and included as one ingredient in the Nine Herbs Charm recommended as a cure for poisoning and infection. Given the generally poor state of health and hygiene we can assume in Dark Age Britain, this suggests that each of the nine herbs would have been in constant demand. I have my suspicions regarding the efficacy of bittercress a medicinal plant, but, by including it on the list of ingredients, our ancestors had clearly devised a way to guarantee a sustained and wide-ranging harvest of the stuff. They probably didn’t like it any more than we do

Let me know what your thoughts are on hairy bittercress, either on Twitter, or by leaving a comment below.