A Greene County Garden in October: Nasturtiums

By Margaret Donsbach Tomlinson

Nasturtiums were beloved by the nineteenth-century Impressionist artist Claude Monet, who planted great swathes of them on each side of an allée in his garden so he could paint them. The flowers, up to two inches wide, bloom in shades of yellow, orange and mahogany-red. A rambling annual, nasturtiums will quickly fill a bed, except for a few non-trailing nasturtium varieties developed for smaller garden spaces. Once they start flowering, nasturtiums will not stop until frost kills the plants, so their magnificent display lasts into October or November, depending on the weather. And yet, nasturtiums are among the few non-native groundcovers that are not invasive. Their large seeds (about a quarter inch in diameter) drop from the plant instead of being wind-carried, and will make new plants the following year, though not usually in large numbers.

Native to South and Central America, nasturtiums were brought to Spain in the mid-1600s by the Spanish physician and botanist Nicolás Monardes and spread from there to the rest of Europe. Monardes included nasturtiums in his 1569 compendium of New World medicinal plants. They have traditionally been used to treat wounds, urinary infections, colds and flu. They do have antibacterial properties. Before staking your health on their reputed benefits, though, keep in mind that Dr. Monardes was not one hundred percent reliable—he also recommended tobacco smoke as a cure-all.

All parts of the nasturtium plant are edible. The flowers have a lightly peppery, sweet flavor. Their common name “nasturtium” came about because people thought they tasted like watercress, whose Latin name is Nasturtium officinale. Carl Linnaeus, the Swedish botanist who gave Latin names to as many plants as he could catalog, called nasturtiums Tropaeolum majus, because he thought the leaves and flowers resembled the shields and bloodstained helmets of vanquished enemies that the Romans hung on their trophy poles, known as tropaeum.

In gentler times and places, nasturtium flowers make a delightful garnish for salads, desserts and fancy drinks. The unopened flower buds taste like capers and can be pickled and used the same way capers are used. Needless to say, if you grow nasturtiums for culinary or medicinal use, they should not be sprayed with insecticides or grown by a heavily traveled road where engine exhaust will settle on them. The plants will, however, thrive under adverse conditions, tolerating a certain amount of drought, poor soil and pollution, as long as the conditions are not extreme. In fact, too much nitrogen will stimulate leaf production at the expense of flowers. Whether you grow them to paint, like Monet did; to eat, like some fancy chefs do; or to enjoy their festive appearance in your garden, easy-care nasturtiums are sure to be a delight to your senses.