Bright yellow nasturtium flowers rise above the foliage for a cheery display in the garden.
In the world of edible annual flowers, nasturtiums are one of the tastiest and easiest to grow. Nasturtiums grow quickly from seed and, depending on the variety, can be grown as climbers on fences and trellises or as bushy plants in a window boxes and containers. Although treated as annuals, these fast growing plants are technically herbaceous perennials. In frost-free areas of the South and West they grow so vigorously that many people consider them weeds.
The biggest surprise with nasturtiums is the taste. In Latin nasturtium literally means 'nose twist.' While most edible flowers have a subtle flavor, nasturtiums knock your socks off with their peppery taste. Plus, it's not just the flowers and buds that are packed with a zippy flavor; the young leaves are tender and edible as well. Nasturtiums are popular with chefs and home gardeners because their colorful flowers not only dress up a plate, they're high in vitamins A, C (10 times as much as lettuce), and D.
While there are several species of nasturtiums, most popular varieties are one of two common species. Tropaeolum majus is a trailing type that can be trained to climb. Tropaeolum minus is a bush type. Nasturtium flowers range from pastels, such as pale yellow, to vibrant oranges and reds, and are available in single or double flowers. You can purchase seed mixes that produce plants in a variety of flower colors, or single-color packets. Most modern varieties have been bred so the flowers stand above the foliage, making them especially striking in the garden.
Here are some of the best selections:
The mounded shape of nasturtiums makes them a nice border plant, and the water lily-like leaves are as edible as the bright flowers.
Nasturtiums flower best in full sun, but still grow well in partly shaded locations, especially in hot-summer areas. They love cool, damp, well-drained soil. If plants begin to flag in the heat of summer, cut them back and they'll regrow and flower again when cooler weather arrives in fall.
Nasturtiums thrive on neglect and don't require rich soil. In fact, if you amend soil with too much nitrogen-rich fertilizer or manure, you'll get lots of dark green foliage and few flowers. In all but the richest soils, amend the planting area by mixing in a 1-inch layer of compost. Plants shouldn't need supplemental fertilizing during the growing season.
Nasturtiums are available in flower colors ranging from the palest yellow to the deepest red.
Nasturtium seeds are large and easy to handle. Sow seeds 10 to 12 inches apart in the garden about a week before the last frost date for your area. Seedlings can also be started indoors, but their taproots make them difficult to transplant. If you do grow them indoors, start them in peat pots. When roots show through the pots' drainage holes, transplant the seedlings, peat pot and all, into the garden.
After sowing, keep the bed well watered and weed-free, and within two months you'll see vigorous growth and abundant flowers. Nasturtiums are relatively trouble-free. Aphids may feed on the new leaves and flowers. Wash these soft-bodied insects off the plant with frequent sprays of water or use insecticidal soap.
For salads, harvest nasturtium flower buds, flowers, and young leaves in the cool of the morning when flowers have just opened. The more heat-stressed the plant, the more pungent the leaves and flowers will taste. Gently wash and dry the flowers and leaves and use immediately or store in a plastic bag in the refrigerator. Although you can eat the whole flower, if the flavor is too strong use only the milder-tasting petals.
Beautiful 'Peach Melba' nasturtium flowers are a delight in any garden or salad.
You can also use nasturtiums in stir-fries, cook them with pasta, and stuff the flowers. More ambitious cooks can try grinding the seeds to use as a pepper substitute and in flavored oils, and pickling the flower buds or immature seedpods to use as a substitute for capers.