Height 20 to 30 cm; spread 20 to 30 cm.
Trailing types may reach 60 cm. Plants have mounding dark-green foliage and medium-sized, slightly fragrant, semi-double and double flowers with crinkled petals. Vegetative and seed-propagated varieties have distinct growth habit.
Whirlybird series: Seed-propagated nasturtiums with gorgeous double flowers—very showy; bushy growth habit; blooms more profusely than other seed varieties and produces blossoms on top of the foliage rather than under the leaves
Apricot Twist: Vegetatively propagated; double apricot-orange blooms.
Hermione Grashoff: Vegetatively propagated; bright-reddish orange double flowers.
Forest Flame: My favourite vegetative variety, with bright apricot-orange, red-splashed double flowers and cream-and-green variegated leaves; looks gorgeous in salads
When growing nasturtiums, the most important thing to note is that seed-propagated varieties and vegetatively propagated varieties have very different care requirements. Seed varieties require less care, but with a bit more work, vegetative varieties offer massive numbers of blooms. If you want to grow the more-robust vegetative nasturtiums, you'll need to buy young plants from a garden centre, because these varieties do not produce viable seed.
How much: Two or three plants; more for ornamental use.
When: One week after the date of average last spring frost.
Where: Full sun to light shade. Excellent in containers or hanging baskets. Vegetative nasturtiums like rich soil; seed varieties prefer average or poor soil. Space each plant 20 to 30 cm apart in the garden, 15 cm apart in pots.
Care and Nurture
Nasturtiums are easy to grow! Water thoroughly, but only when soil is dry. Vegetative nasturtiums require heavy feeding, but seed nasturtiums require little, if any, fertilizer. Vegetative nasturtiums should be pinched and deadheaded regularly to promote continuous flowering and bushy growth.
All parts of the nasturtium are edible—the leaves, the flower buds, and the flowers. The buds can be used as a substitute for capers or like a mild peppercorn in salads.
For best flavour: Choose young, tender growth—young leaves and newly opened flowers.
Leaves: Clip the leaf stalk where it attaches to the main growing stem; cut stalk off leaf body and discard.
Flower buds: Harvest while the bud is still tightly closed. Clip cleaning from the stalk.
Flowers: Harvest flowers after they have opened fully. Clip the stalk two or three centimetres from the base of flower head.
Preserving the Harvest
Leaves, flowers, and buds should be used fresh. They cannot be dried or frozen, but may be refrigerated briefly.
- If the plants get leggy, don’t be afraid to cut the plants back. I cut my plants back quite severely, then water and fertilize well. They grow back with a vengeance, although they will look ugly for a few days. If you’re planning a week or two of holidays, cut the plants back by up to one-third before you leave. By the time you return, the plants will have reflushed.
- Nasturtiums are a good choice for children’s gardens because the pea-sized seeds are big enough to be easily handled by small fingers and the plants grow very quickly, with big, bright flowers.
- Nasturtiums come in a variety of colours, including cherry, gold, mahogany, orange, peach, and scarlet, with new shades making their debut each year.
- Traditional nasturtium varieties attract hummingbirds and bees. But the spurs cause the flowers to face the ground, hiding the them under the foliage. We recommend spurless varieties such as the Whirlybird series, so that the flowers are held well above the foliage, creating a much more colourful display. Nasturtium spurs contain a sweet nectar and are considered a delicacy.
- Nasturtiums make a lovely short-stemmed cut-flower.
- The Latin name nasturtium is derived from the words nasus tortus (twisted or convulsed nose), a reference to the plant's pungent scent.
- In the language of flowers, nasturtiums signify patriotism. Fittingly, Dwight Eisenhower included nasturtiums in his recipe for vegetable soup.