Bright, bold, and cheerful, nasturtiums are among the easiest flowers to grow.
With only a hint of care and attention, these fast-spreading annuals put on a summer-long show of vibrant, beautiful flowers.
And they’re entirely edible! Every part of the plant, including seeds, leaves, and flowers, has a tasty, distinct flavor.
The flowers and leaves of the Tropaeolum have a refreshing, peppery taste, and pickled seeds make an excellent substitute for capers. In addition, both flowers and leaves make a gorgeous garnish on any summer plate!
One species, T. tuberosum, even produces an edible tuber, and is an important food source in the Andes mountains of South America.
Nasturtiums belong to the Tropaeolum genus of the Brassicaceae (cabbage) family, and numerous popular garden cultivars are available, including dwarf, bush, climbing, and trailing varieties.
The plant goes by various common names including Indian cress, Mexican cress, and Peru cress.
The Nasturtium genus is also a member of the Brassicas, but this botanical classification properly refers to watercress plants.
Because of its intense flavor, watercress got dibs on the name – which means “twisted nose,” originally from the Latin phrase nasus tortus. Apparently, a twisted nose was a common reaction to eating their pungent leaves!
The flowering garden annual was also given the common name “nasturtium” because it produces an oil with a similar peppery flavor to that of watercress.
Native to South and Central America, this fast-growing herbaceous annual has numerous round, green leaves and trumpet-shaped flowers, often with intense tropical colors, that sit atop long, slender stalks.
A Garden Trophy
Tropaeolum was introduced to Spain from the Americas in the mid-1500s, and was commonly used as a salad ingredient in the same way as that of garden and watercress.
Famed Swedish botanist Carl Linnaeus named the genus Tropaeolum because they reminded him of a Roman custom of raising a trophy pole (or tropaeum) after a victorious battle. The round leaves made him think of military shields, while the deep red flowers conjured images of bloodstained helmets.
Flowers come in deeply intense hues of cream, yellow, orange, and red, which are set off beautifully by the sea of green leaves.
Highly useful, this annual has many attractive applications in the garden.
Nasturtiums can be grown in the landscape or containers, and they make an ideal ground cover in areas with poor soil. They also do a yeoman’s job of being a companion to other plants, and make an attractive addition to floral arrangements, with the flowers giving a light, fruity scent.
Simple and easy to grow, with over 100 varieties available, they come in cascading, climbing, and bush forms. Nasturtiums require an absolute minimum of care, and will thrive even when neglected.
Truth be told, if grown in soil that’s too rich, or after the application of fertilizer, abundant foliage will result – but with few flowers. But this isn’t necessarily a bad thing…
The fast-growing greenery makes a good seasonal screen for hard-to-grow areas, such as under decks and in other shady spots, or for areas with poor soil.
Choose the old-fashioned climbing and trailing varieties for their long-limbed use in vertical spaces, like on trellises or fences, or as sprawling ground covers and weed barriers.
T. peregrinum gives us cultivars such the yellow ‘Canary Creeper,’ while the ‘Moonlight’ series of climbers comes from T. Lobbianum.
T. minus is a small bush species that makes an excellent aphid trap to protect beans, squash, and other plants in the veggie patch.
Plant near the crops you want to protect from the sap-sucking pests, then hose off aphids or apply a gentle and natural insecticidal soap.
To make your own safe, pest-busting soap, use a pure, additive-free brand like Castile’s, available on Amazon. Mix in a ratio of 1 tablespoon soap per 1 quart of water. Or drop a bar of Ivory into a gallon of water overnight.
Shake gently, and pour into a mister. Give the solution another good shake, then apply to infested areas.
Or, the use of a few 10-inch planted pots that can be easily moved is a good option for small spaces.
Use compact trailing varieties from T. majus – such as the fire engine red ‘Empress of India’ and the multi-colored ‘Fiesta’ blends – as spectacular spillers to trail from window boxes and hanging baskets, or over rock walls.
For the Dinner Plate
And remember to grow some for your kitchen garden – they add a fresh, peppery taste and a touch of bright beauty to the dinner table. Of course, they need to be grown naturally and without the use of chemicals!
For an appy (or an “app,” for the American readers), stuff flowers with softened cream or goat cheese mixed with fresh herbs. Serve on a tray scattered with nasturtium leaves.
Minced leaves and flowers are delicious when blended with lemon butter to accompany steak, seafood, veggies, or fresh artisan breads.
And to add a piquant flavor to salads and pastas, use whole or shredded leaves and flowers.
You can also pickle immature green seeds. Known as “poor man’s capers,” they make an excellent substitute for the real thing.
Plus, as a plate garnish, their bold beauty is delightful!
Care and Cultivation
Nasturtiums do best in poor to average soil, slightly on the acidic side. And good drainage is a must.
For the most abundant flowers, grow in full sun. In partial shade, the foliage will be bigger, but with fewer flowers, and plants will tend to sprawl more.
Seeds should be sown after danger of frost has passed at a depth of 1/2 inch – and they need the darkness, so make it a true 1/2 inch. They will germinate in 10-14 days.
For faster sprouting, soak the seeds in lukewarm water overnight. Plant directly in the ground, or in containers where you want them to grow.
They can also be started indoors 4 to 6 weeks before the last frost date; however, they sow and sprout so eagerly, this is usually unnecessary.
Ensure the seeds are kept moist during the germination period, and water in dry weather.
Tougher than they look, once established, nasturtiums can handle periods of drought and high temperatures – although they can suffer from scorch in excessively hot afternoon sunshine.
Nasturtiums don’t require fertilizer, and even when grown in containers, they won’t require the same amount of feeding as other annuals.
If the plants get a bit strung out or lanky, prune back to a desirable size and they’ll quickly produce new growth. The occasional grooming or deadheading of flowers will also prolong blooming.
Grown in containers, they benefit from the occasional trim to maintain a compact shape, and to keep flower production high.
Very adaptable, nasturtiums can succeed in poor soils, dry conditions, and shady areas, making them the go-to flower for those stubborn spots where other plants struggle or perish.
They also set copious amounts of seeds with abandon, and will self-seed readily. Collect ripened seedpods from the ground from late summer until winter. Store seeds in a paper envelope in a cool, dark environment until ready to plant the next spring.
Once they’ve found a happy spot (which is pretty much anywhere), nasturtiums will produce a rich supply of flowers until touched with frost.
In addition, their pretty fragrance and longevity make them a good option in a vase of cut flowers.
Largely disease free, powdery mildew may appear in wet conditions. Thin out infected areas and allow the soil to dry out before watering again.
And because of their many outstanding characteristics and quick growth, nasturtiums are always a good choice for children’s gardens.
As mentioned, nasturtiums are a natural trap crop for aphids, and work well for this purpose when planted with green beans, runner beans, and squashes.
They also deter other pests like whiteflies and cucumber beetles, and attract beneficial predator insects such as ladybugs, lacewings, and parasitic wasps (teensy, non-stinging wasps).
Tropaeolum Plant Facts
- Edible – leaves, flowers, and seeds can all be used in the kitchen.
- A premier no-fuss plant!
- Prefer poor soil and need no fertilizing
- Will grow in sun or shade.
- Can withstand dry spells when mature.
- A hardworking companion plant in the veggie garden.
- One of the easiest plants to grow from seed.
- A must for children’s gardens!
- Benefits from pruning to restore shape and flower production.
Where To Buy
Remember, if you plan to use nasturtiums for edible purposes, buy organic seeds like this ‘Kaleidoscope’ mix of bright reds and oranges with swirled bicolors from David’s Garden Seeds. And use natural, non-toxic pest control practices in your garden.
Organic ‘Kaleidoscope’ Mix, available on Amazon
For something that provides a unique pop of color, try ‘Baby Rose.’ This cultivar has dark green foliage and deep rose-colored flowers. Unlike other vining types that are eager to spread, this variety has a tightly mounding habit with blooms that are held upright, so it’s perfect for containers and makes a nice addition to the herb garden as well. Full spread maxes out at 10-12 inches.
Packets of 50 seeds each are available from Burpee.
For window boxes, hanging planters, rockeries, and xeriscaping, try trailing types like this open-pollinated trailing mix of red, orange, and yellow blossoms from David’s Garden Seeds, available on Amazon.
For ground covers, trellises, or fences, a climbing type such as the scarlet ‘Spitfire’ fits the bill.
You can find it at Renee’s Seeds, also available on Amazon.
Finally, ‘Peach Melba’ is an heirloom variety that you might enjoy, marked by yellow blooms with decorative blotches toward the center of each in a darker shade that ranges from orange to maroon. Another compact variety, its spread maxes out at 10-12 inches, so it will behave in containers and small spaces.
Packets of 50 seeds each are available from Burpee.
The Twisted Nose
It’s easy to understand why nasturtiums are so highly valued in the garden – they pack a lot of versatility into their growing season!
Simple to grow from seed, hardworking and versatile, these no-fuss annuals also provide dazzling color from spring until frost.
They can be used as ground covers, as spillers from hanging pots, for climbing, as trap plants for the veggie patch, and for cut flowers. Plus, they are entirely edible with a lively, piquant flavor. Now, that’s one talented plant!
Remember to keep seeds moist while germinating, provide a sunny location for the best flower production, give them excellent drainage, and water when dry.
And ease up on the fertilizer! Unless you want to use the foliage as a fill-in plant for tricky spots, no feeding is required.
Do you folks have any questions or nasturtium problems we can help you with? Drop us a line in the comments below, or join us on our Facebook page!
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Photos by Lorna Kring. © Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Product photos via David’s Garden Seeds and Renee’s Seeds. Uncredited photos: Shutterstock. Last updated April 12, 2019. With additional writing and editing by Allison Sidhu.
About Lorna Kring
A writer, artist, and entrepreneur, Lorna is also a long-time gardener who got hooked on organic and natural gardening methods at an early age. These days, her vegetable garden is smaller to make room for decorative landscapes filled with color, fragrance, art, and hidden treasures. Cultivating and designing the ideal garden spot is one of her favorite activities – especially for gathering with family and friends for good times and good food (straight from the garden, of course)!