Nasturtium Gems

“Nasturtium is an herb which for me has three uses: it lights sober herb beds with its bright colors of orange and yellow; all summer it decorates salads with leaves and gay flowers; and in the autumn it provides green seeds for pickling. Does it not earn for itself a place in an herb garden?”

–Annie Burnham Carter, In an Herb Garden (Rutgers University Press, 1947)

Bright, versatile and easy to grow, nasturtiums are among my very favorite garden flowers. I love even their name: a combination of the Latin nasus for “nose” and tortus for “twisted,” describing the way our noses twist or wrinkle when we inhale their spicy scent. Some sources say their botanical family name Tropaeolaceae comes from tropaion, the Greek word for “trophy,” due to the plant’s shield-like leaves and helmet-shaped blooms. But because of their exuberant nature, I affectionately refer to these garden rowdies as “nasties.”

Nasturtiums effortlessly fill garden space with mounds of fun foliage even before their showy bloom colors appear. The unusual leaves are rounded with wavy edges, and their stems attach to them from the bottom, directly in the center. Leaves range in color from gray-green to bright green, blue-green and variegated, with each bearing a pretty, starlike pattern of veins. The spurred, trumpet-shaped flowers are available in a palette of bright colors–from tropical hues, such as creamy yellow, peach and coral, to primary yellow and red to vivid orange, gold and even mahogany.

No wonder Monet cultivated nasturtiums liberally throughout the gardens at Giverny, where he captured their mounding masses of jewel-colored blooms in many of his famous paintings. (See “Monet’s Garden of Living Color.”) And Thomas Jefferson, who planted nasturtiums in his garden every year, lamented when he couldn’t get enough seed to fill a 30-by-57-foot bed with them!

Garden Groundwork

We nasturtium lovers owe our gratitude to the Spanish conquistadores for first bringing the fiery-colored Tropaeolum majus from its native South America to Europe more than 500 years ago. In the garden, this 8- to 10-foot vine requires a supporting fence or trellis. The more commonly grown garden cultivars are shorter in stature (8 to 20 inches tall) and loosely mounded in form. I like to plant them along the edge of a border, at the top of a wall or in a pot or hanging basket where their sprawling stems can spill gracefully over the edges.

Nasturtiums start easily from seed in average soil and full sun. Here in Zone 7, I sow them directly into the garden in late March or early April, about the same time that I plant early greens. I like the ritual–going about the kitchen garden with my seed packs and poking the fat, bumpy-round seeds into the cold earth along the edges of the bed. For masses of color, I plant the seeds about 8 to 12 inches apart.

When the plants are up, keep them well watered. But don’t feed them too much nitrogen or you’ll get massive leaf growth with few blooms.

Harvest the edible leaves regularly to keep the plants bushy. Remove and discard the stems, then rinse the leaves and use them like lettuce. When harvesting flowers, pick them with long stems, and keep your bouquet in a glass of water until you are ready to prepare the blossoms. When you’re ready, rinse the blooms gently and shake or pat them dry. Remove the stem and use the whole bloom, or gently tear it into separate petals.

Plant Profile

• Nasturtium (Tropaeolum majus)
• Family: Tropaeolaceae
• Also Goes By: Indian cress, trophy cress, trophywort
• Native Habitat: Peru, parts of South America
• Plant Type: Annual
• Growth Habit: Bushy cultivars grow 8 to 20 inches tall; climbers can reach 6 to 10 feet or more.
• Light: Best in full sun; in partial shade, produces more leaves and fewer flowers
• Water: Moist but not wet; will tolerate some drought
• Soil: Friable and porous garden loam; also does well in pots
• Propagation: Plant seeds in spring

Kitchen Prep

Both the fresh foliage and flowers of nasturtium add a pleasant hint of heat and pungency to many summer dishes. The leaves, which are high in vitamin C, add a peppery cress-like flavor to salads, sandwiches and green sauces. (Click here for Salsa Verde with Nasturtiums recipe.) When shredded, they make a flavorful accent for pasta, rice, couscous or chicken salad. Or chop and sprinkle them on pizza.

The blossoms have the same peppery quality as the leaves, but are milder, with a hint of a floral scent. The whole blooms make beautiful holders for cold salads–egg, chicken and vegetable–as well as cheese spreads. (Click here for Nasturtiums Filled with Guacamole recipe.) Because they are a bit fragile when filled, I like to place the filled flowers on vegetable or bread slices so they can be picked up more easily. Whole flowers also can be used in salads or as garnishes. Or use them to make a lovely, colored vinegar. (Click here for Nasturtium Vinegar recipe.) 

You can cut both the flowers and leaves into chiffonade (thin ribbons) to blend with butter, or toss them with egg salad, noodles, vegetables or fish. The unopened buds, marinated in wine or vinegar, make an unusual refrigerator pickle. Even the seeds can be harvested and used; when pickled, they make a suitable substitute for capers.

Here are three of my favorite ways to use nasturtiums.

Nasturtiums Filled with Guacamole

Makes about 20 appetizers

Piquant nasturtium blossoms are a wonderful foil for guacamole, and the jicama provides a nice, crunchy base. If you don’t have jicama, Jerusalem artichokes or cucumber slices are a good substitute. This recipe is excerpted from my book Flowers in the Kitchen (Interweave Press, 1991).

• 1 large avocado, preferably Hass
• 2 teaspoons lime juice
• 1 small tomato, finely chopped
• 2 tablespoons finely minced onion
• 1 jalapeño or serrano chile, seeded and finely minced
• 1 small clove garlic, finely minced
• Salt, to taste
• About 20 nasturtium blossoms
• 1 small jicama
• Lime juice

1. Peel avocado and remove pit. Mash avocado in a bowl with a fork and add lime juice. Blend in tomato, onion, chile and garlic. Add salt to taste. Let guacamole stand, covered, while preparing the nasturtiums and jicama.
2. Rinse nasturtiums carefully and pat them dry. Peel jicama and slice it about 1/4-inch thick. Cut the slices into pieces about 2-by-2 inches in size. (They don’t have to be perfect squares–leave the rounded edges.) They should be just the right size to accommodate a nasturtium filled with guacamole. Squeeze a little lime juice over the jicama slices.
3. At this point, the guacamole, jicama and nasturtiums can be kept for a few hours in the refrigerator, if necessary. To assemble the appetizers, hold nasturtiums at the base and use a teaspoon to fill them carefully with the guacamole. Set each filled nasturtium on a slice of jicama and arrange on a serving platter. The prepared appetizers can be kept very briefly in the refrigerator or served immediately.

Salsa Verde with Nasturtiums

Makes about 2½ cups

This sauce goes well with any vegetable whether grilled, steamed, oven-roasted or served as crudité; it also is good with pasta or simply prepared meat, chicken or fish. Vary the herbs, using what you have on hand or what is in season. (For example, replace some of the parsley with basil, or use tarragon or dill instead of marjoram.) You also can substitute watercress or arugula for the nasturtium leaves.

• 1½ cups packed Italian parsley leaves
• 1½ cups loosely packed nasturtium leaves
• ¼ cup loosely packed marjoram or oregano leaves, or a mixture
• One 1-inch slice country bread, crusts removed
• About ½ cup olive oil
• ¼ cup minced sweet onion
• 3 garlic cloves, minced
• 2 tablespoons white wine vinegar
• 1 tablespoon capers
• Salt and freshly ground pepper, to taste

1. In a mortar, pound parsley, nasturtium and marjoram or oregano leaves with a pestle, or chop leaves in a food processor. Soak bread in a little water for 10 minutes, then squeeze most of the liquid from it. Add bread to the mortar or food processor and mix it with the herbs.
2. Add olive oil to herbs as if making a mayonnaise, a few drops at a time, blending or pulsing to incorporate. You might need only ? cup of oil; it should be a sauce consistency. You also can add a few tablespoons of water to thin it down, rather than all oil.
3. When olive oil has been added, blend in onion, garlic, vinegar and capers. Season the sauce with salt and pepper.
4. Let sauce stand at least 30 minutes before using. Adjust the seasoning and serve at room temperature. The olive oil will not emulsify completely; a little will remain on top of the sauce. Store any leftover sauce in a tightly covered glass container in the refrigerator for up to one week.

Nasturtium Vinegar

Makes 1 pint

Nasturtiums make a pretty, peppery-flavored vinegar. Choose bright blooms to make the most colorful vinegars. Although “nasties” can stand on their own in vinegar, these complementary herbs can be added: basil, chile peppers, chives, garlic, lemon herbs and/or marjoram.

• About 1 to 1½ cups loosely packed nasturtium flowers (plus other herbs, if desired)
• 1 pint white wine, rice wine or apple cider vinegar

1. Harvest your flowers and herbs on a sunny morning, rinse them if necessary and pat them dry. Bruise them slightly to release their flavor. Fill a clean jar about half to three-quarters full of the flowers and herbs, then cover them with vinegar. Use plastic rather than metal lids because the vinegar’s acid eventually will leach out and corrode the metal. (You can buy plastic lids to fit canning jars if you have only metal lids.) Label the jars.
2. Place the jar in a cool, dark place. If you begin steeping the herbs in the vinegar in the morning, you’ll have a mildly flavored vinegar you can use by evening. The longer the vinegar stands–up to 4 weeks–the more flavor it will have. Eventually, however, the flowers and herbs will deteriorate and the flavor will not be as bright. To avoid this, sample your vinegar 10 days to 2 weeks after you mix it, and continue to taste it every few days thereafter.
3. When your vinegar has reached its full flavor, strain out the flowers and herbs. Strain the mixture again through coffee filters to achieve a crystal clear vinegar. Using a funnel, pour the vinegar into smaller bottles and label. Store the vinegar in a cool, dark place and use within a year.

— Contributing editor Susan Belsinger frequently writes and lectures about herbs. She lives in Brookville, Maryland.