Beautiful, easy to grow, and delicious, no garden should be without Nasturtiums! Nasturtiums have been a garden favorite for generations, and rightly so. With boldly-colored, exotic-looking flowers that float above elegant lily pad-shaped leaves, Nasturtiums are carefree plants that bloom all summer long without asking much of anything from the gardener.
That's right: no deadheading and no fertilizing. They also attract butterflies and hummingbirds, and are said to repel less-desirable insects, deer, and rabbits. The greatest charm of Nasturtiums may, however, be their culinary usage. All parts of the plant are edible, and have a spicy, peppery tang. Fresh leaves and flowers are a zesty addition to salads or sandwiches, or can be stuffed and sautéed, or made into pesto.
Unripe Nasturtium seed pods can even be pickled to make an excellent substitute for capers. The flavor of nasturtium is reminiscent of watercress, and there is sometimes confusion between the two plants: the botanical name for watercress is Nasturtium officinale, even though it is a member of the mustard family and not related to the flower known as Nasturtium.
At home in the ground or in containers, the growth habit of Nasturtiums is usually described as either "mounding" or "trailing". Mounding Nasturtiums form a neat, round bundle, usually about 10 to 12" wide and slightly less tall. Trailing, or vining, varieties can climb 5' or more if given a trellis, or can be allowed to sprawl and ramble on the ground. They also look good as the spiller accent in pots. Whether you have a veggie garden or a formal border, leave some room for a few Nasturtiums!
Some varieties you can find at Portland Nursery include:
Mounding variety with white-splashed, variegated leaves. Flowers bloom in shades of orange, red, rose, yellow, and salmon. 10-12".
Buttery-yellow flowers with frilly duck foot-shaped petals. Mounding, 10-12".
'Dwarf Jewel' Mix
Mounding plants available in a variety of rich jewel tones. 6-12".
'Empress of India'
Rich scarlet flowers sit above lovely blue-green foliage. Mounding plants, to 12".
Semi-double flowers in a range of bright colors. Trailing habit, to 5' tall if trellised.
Yellow, cream, or orange-colored flowers have a distinctive red or purple spot at the base of each petal. Mounding, 8-12".
An heirloom from the late 1800s. Pale, creamy-yellow flowers. Trailing, 5-8' tall when trellised.
Heirloom variety. Creamy, peach-colored flowers with a splash of red at the base of each petal rise above blue-green foliage. Compact growth, 10-12".
Mounding variety available in rich tones of red, orange, pink, and gold. 10-12".
Tropaeolum peregrinum Canary Creeper, Canary Bird Vine
A tender perennial cousin of Nasturtium, this vigorous vine has deeply-lobed blue-green leaves and frilly yellow flowers that resemble tiny birds. Climbs 8-12' when trellised. As with Nasturtiums, the leaves and flowers are edible.
Common name: Nasturtium
Origin: Central and South America
Culture: Very easy to grow. Nasturtiums prefer leaner soils. Using fertilizers on Nasturtiums tends to make plants put out lots of leaves and few blossoms. They prefer full sun, but can do well in part sun or dappled shade situations. Nasturtiums look their best during cooler weather in the summer.
Maintenance: The tall or climbing varieties sometimes benefit from slight pruning. Removing yellow leaves keeps them looking fresh. Deadheading is not necessary. Average watering needs; water more frequently when the weather is hot.
Pests & Diseases: Prone to aphids, usually late in the season. Nasturtiums are sometimes used as a trap crop to lure aphids away from more susceptible plants. Look for aphids on the undersides of leaves, and remove and destroy affected leaves, or use a strong jet of water from the hose to knock pests off.
Insecticidal soaps and horticultural oils can be applied, but Nasturtiums are very resilient, so it's not usually necessary. Slugs and caterpillars sometimes dine on young plants early in the season.
Propagation: Very easy to start from seed. The seeds are large and easily handled, making them ideal for children's gardens. Start seeds indoors 2-4 weeks before the last frost date. Be careful not to start too early, as Nasturtiums are very susceptible to cold damage.
It's better to sow seeds directly in the garden in April or May, until as late as July. Nasturtium seeds germinate and grow rapidly in warm soils. Young plants are also available to purchase in summer. Take care in transplanting; Nasturtiums resent having their roots disturbed. Nasturtiums tend to reseed.