Nasturtiums - Cool Season Flowers with Hot Season Flair

Nasturtium Flowers
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Overview and Description:

Nasturtium plants are loved for their rich, saturated jewel-toned colors. They are fast and easy to grow and, in fact, do best with a little neglect. There are varieties for almost every gardening purpose: bushy plants for borders and edges, trailing plants for walls and containers, and climbers to add dramatic height in a garden. The leaves and flowers are edible, with a peppery tang, and even the seed pods are used as a substitute for capers.

Check out this nasturtium capers recipe.

Nasturtiums plants grow very full, with lots of bright green leaves and spots of brightly colored blossoms poking out of masses of foliage.

  • Leaves: Rounded, like a water lily.
  • Flowers: An open funnel shape with a curious little claw or spur on the underside. They are most often seen in rich shades of yellow, orange, ,pink, red and mahogany but there are also varieties in subdued shades of butter yellow and cream. The ‘Alaska’ Series and the climbing ‘Jewel of Africa’ have variegated leaves.

Botanical Name:

Tropaeolum

Common Name(s):

Nasturtium

Hardiness Zones:

Some varieties are perennial in USDA Zones 9 - 11, but most are annuals plants, growing from seed to seed in one season.

Mature Size:

As with most plants, the mature zine with vary, depending on the type of nasturtium you plant and the growing conditions.

  • Bushy varieties  can get to about 12 inches(h) - 18 inches (w).
  • Trailing nasturtiums grow about 3 - 4 ft. long.
  • Climbing nasturtiums can reach about 10' ft. high.

Exposure:

Nasturtiums will grow in either full sun to partial shade. They will bloom best in full sun, but they plants prefer not to be in extreme heat.

Bloom Period:

Expect flowers from early summer through fall in cooler climates.

In milder growing conditions, nasturtiums bloom fall through spring, and tend to fade in summer heat.

Design Tips:

Nasturtiums will spill beautifully over walls and onto pavers, when used as edging plants. They also hold up very well in containers. Climbing varieties will amble up and through shrubs. Bushy, ground hugging nasturtiums will fill in blooming gaps among complementary colored day lilies and roses. And you can use clusters to brighten up the vegetable garden.

One thing to be aware of, when choosing which nasturtium to grow, is that the flowers of some varieties can be obstructed by their amble foliage. If you are growing your nasturtiums at ground level, choose one of the newer varieties that hold their flowers above their leaves, so you can easily see them.

Suggested Varieties:

  • Alaska Series - Bushy, dwarf plants with heavily variegated foliage and the blossoms are held above the foliage.
  • Jewel Series - Bushy, dwarf with double and semi-double blooms. A profuse bloomer, but flowers can tend to get lost under the foliage.
  • 'Peach Melba' - Busy, dwarf with semi-double buttery yellow flowers splashed with orangy-red centers. Good for containers.
  • 'Canary Creeper' (T. Peregrinum) - Perennial vine in the nasturtium genus, with yellow flowers that look like bird’s wings.

Nasturtium Growing Tips:

Nasturtiums are usually started from seed, so you won’t often find them available as plants at nurseries. However, the seeds germinate quickly and the plants will be up and blooming in little time.

Seeds can be sown directly in the garden, when the soil has warmed, or started indoors about 2-4 weeks earlier. Nasturtiums don’t especially like being transplanted, so starting indoor seedlings in peat or paper pots will reduce transplant shock. Once planted, they tend to take care of themselves.

Maintenance:

  • Nasturtiums like regular weekly watering. They will survive some drought conditions, but flowering will diminish and the foliage can begin to look ratty.

     

  • Deadheading is not usually necessary, unless a plant has been stressed and is holding on to spent blooms.

     

  • They do, however, thrive in lean soil. Don’t feed nasturtium plants at all during the growing season. Fertilizer causes them to put out more foliage and less flowers.

Pests & Diseases:

  • Nasturtiums are very prone to aphids and are sometimes used as a trap crop in vegetable gardens. A strong blast of water is usually enough to get rid of the aphids.

  • They can also be prone to flea beetles, slugs and the caterpillars of cabbage white butterflies.