Plants to Grow Beyond the Pale

By Shirley Barker, Special to the Planet
Tuesday August 07, 2007

As noted in a previous article, globe artichokes are perennial plants that need a permanent spot outside the vegetable area designated for a four-year rotation plan. These are not the only plants needing their own separate place: rhubarb and horseradish are others. 

Plant horseradish among the vegetables and plan on spending the next two years trying to get rid of it since it spreads like wildfire. The smallest piece of root left behind is likely to regenerate. Planting it in a tall cylinder with a diameter of 12 inches is recommended by some experts as a way to confine it. This was no deterrent to mine, it simply tunneled beneath and popped up all over the place.  

Since horseradish does not need the lush loam of a well-tended vegetable garden, it will do quite well with leaner fare in some out-of-the-way corner. Like globe artichokes, it will die down and return bigger and better than ever, slowly expanding over time. Harvesting the outside roots helps to curb its spread. Like rhubarb, it thrives on winter chill.  

Horseradish makes an underused yet addictive condiment. Roast beef without horseradish is unimaginable. It goes well with smoked fish and makes a sharp contrast to sweet beets. In medieval England it accompanied oysters. There were oyster beds in the coastal village where I grew up, said to date from Roman times. Since gardeners there still dig up Roman trinkets, this seems plausible. Alas, some contaminant destroyed them, although the large square beds are still visible at low tide. Given the pungency of the navy blue mud that is revealed then, intimately familiar to sailors who have miscalculated the tide, one cannot imagine any mollusc therein fit to eat.  

Scrape and grate the roots after digging and washing. A potato peeler is helpful in carving across, around and into the twists and channels of the root. Add a touch of vinegar and salt to the gratings and stir them into thick cream. This is horseradish sauce as it should be and rarely is. If space is at a premium in your garden and the craving for it hits, hurry to Brennan’s, our beloved (though slated for demolition) Irish eatery on Fourth Street just south of University Avenue, whose creamy horseradish, until I started to grow my own, used to leave me gasping, helping to expand my jaws to accommodate their massive sandwiches. 

Horseradish is a crucifer, Armoracia rusticana, and has been in cultivation for hundreds of years. It grows wild here now, introduced by early settlers. It is one of the bitter herbs of Judaism, eaten during Passover. It is the main component of the Japanese wasabi, tinted green. Creamy white is its true color, unless it has oxydized, when it turns brown. (Quickly adding just a little of the vinegar as soon as it is grated prevents this.) The radish part of its common name derives from the Latin for root, radix. The horse part seems to have been corrupted, from an obscurely related word, by the English, as is their wont. Anything with horse in it tends to mean coarse, as in the horse bean and horse gram, both used for fodder. One can imagine some raised equine eyebrows if A. rusticana is added to the morning mash. 

Like horseradish, rhubarb in full growth bears huge, lush leaves that add a decorative touch to the flower garden. Tucked into the herbacious border, when the leaves have died back to a shriveled unsightly heap the plant will be hidden by the Michaelmas daisies, the lupines, the asters, and the oriental poppies. Since, as noted, it needs winter chill to thrive, it is not always successfully grown in Berkeley’s horticultural zone. But it will love the side dressings of compost and mulches usually given to flower beds. 

If rhubarb seems to be doing well in early spring, growth can be hastened by up-ending a bushel basket over the entire plant, forcing the edible stems upwards to seek the light, and making them tender. Flowering stems should be removed, to prevent diversion of the plant’s energy from its stalks. Since nature’s goal is always to set seed, the rhubarb-lover must intervene if edible stalks are desired. 

The origins of rhubarb, Rheum rhaponticum, are uncertain. One ancestor (it is thought to be a hybrid) might have been a wild Siberian. It is in the polygonaceae family, where buckwheat belongs, so definitely has a touch of the Russian in it. Furthermore, the specific epithet is believed by some to derive from Rha, the ancient name for the river Volga, on whose banks it used to grow wild. No wonder it enjoys frosty winters. 

Some purists call rhubarb a vegetable because we eat the stalks, not the fruits. Do they call the globe artichoke a fruit, since we eat its flower buds? As T.S. Eliot pointed out in another context, the naming of things is a serious matter. As he then goes on to demonstrate, it has its absurdities. Names are map-like, enormously helpful and interesting, yet not fundamentally essential. 

Like so many plants under cultivation for centuries, both horseradish and rhubarb reputedly cure many ailments. It seems likely that both might have purgative properties if eaten in excess. There seems to have been some contest between beets and horseradish as to which, in the opinion of the Delphic oracle, was worth its weight in gold. Since horseradish certainly clears the sinuses and contains some vitamin C, and so might help to alleviate the symptoms of the common cold, it is surely worthy of some prize.  

Rhubarb at one time was used to replace tobacco, only discernible as bogus when scrutinized under a microscope. It still, as far as I know, has one endearing usage: when a group voice is required on stage or screen, to be heard at a distance, the actors traditionally murmur “rhubarb rhubarb.”  

Rhubarb is made into wine in English villages, providing a Miss Marples touch if improperly made, since an incorporation, accidental or not, of a leaf or two would make a lethal digestive. The high amount of oxalic acid in the leaves is what has been known to kill. I’d rather take my rhubarb safe and solid, digging into a dish of the pink tart stalks stewed with plenty of sugar and strewn with ripe strawberries, perhaps tucked under a pie crust and baked until golden and oozing rosy juice.