Nasturtium are tremendous all-round plants for the garden. They can be perennials or annuals, climbing or border plants and also do well in containers. What is more, both leaves and flowers are edible, and can add a peppery, rocket-like taste in salads.
Nasturtium are in the genus Tropaeolum and native to the warm climates of Central and South America. Like Dahlias, Nasturtium were brought back to Europe by the Spanish conquistadores in the 18th century.
Vibrant Nasturtium flowers come in a variety of hot colours adding real summer punch to your garden. Even better, these are not difficult plants to grow, as they’ll even thrive with a little bit of neglect.
Here’s what you need to know about growing Nasturtiums.
Location and sunlight
To get the best out of your Nasturtiums, choose a location that gets full sun to partial shade. These plants flourish in areas with at least 4-6 hours of direct sunlight each day.
When choosing a location for your Nasturtium, you should also make sure there is enough space for the roots to spread out without being crowded by other plants.
If you live in an area with hot summers, afternoon shade may be necessary to prevent the leaves from burning.
Soil requirements
Nasturtiums are not picky about soil quality; they actually prefer poorer soils. The key is well-draining soil to prevent root rot. Avoid rich soils and over-fertilising, which can lead to more leaves and fewer flowers.
The plant does best in sandy loam soils that have good drainage—Nasturtium roots won’t tolerate sitting in waterlogged dirt for long periods of time.
If your yard or garden has clay soil, you can still grow Nasturtiums by planting them in raised beds or mounds so the water drains away quickly after heavy rain.
Watering
When growing Nasturtiums, ensure that the soil is slightly moist but not waterlogged. Regular watering is essential, especially in dry periods. But be careful not to overwater. Mulching can help retain moisture and suppress weeds.
Direct sowing of seeds
Sow Nasturtium seeds directly in the garden after the last frost.
Plant seeds about 1/2 inch deep and space them 8-12 inches apart. This method often leads to better germination rates and healthier plants.
Companion planting
Plant Nasturtiums alongside vegetables or other plants that are prone to pests. They can naturally repel insects like aphids and can protect your garden without the need for chemical pesticides.
Nasturtium varieties
Opt for early-flowering Nasturtium varieties if you live in areas with shorter growing seasons. Varieties like the ‘Jewel Mix’ grow quickly and can bring beauty to your garden sooner.
Here is a run down of some of the best Nasturtium varieties to grow
1. Tropaeolum majus ‘Empress of India’
- Color: Deep crimson flowers.
- Foliage: Dark green, almost bluish leaves.
- Growth Habit: Compact, bushy growth ideal for borders and containers.
- Height: Around 12 inches.
Why it is one of the best varieties: ‘Empress of India’ variety is prized for its striking contrast between dark foliage and crimson flowers. Its compact size makes it perfect for small spaces and containers. It is a great addition to any garden, providing a rich, splash of colour.
2. Tropaeolum majus ‘Alaska’
- Color: Mix of red, orange, yellow, and cream flowers.
- Foliage: Variegated green and white leaves.
- Growth Habit: Spreading, ideal for ground cover or hanging baskets.
- Height: 10-14 inches.
Why it is one of the best varieties: ‘Alaska’ is known for its unique variegated foliage, which adds interest even when the plant isn’t in bloom. Its diverse flower colours create a vibrant display. It thrives in various garden settings from ground cover to hanging baskets.
3. Tropaeolum majus ‘Jewel Mix’
- Color: A vibrant mix of red, orange, yellow, and cream double and semi-double flowers.
- Foliage: Light green, rounded leaves.
- Growth Habit: Compact and bushy, excellent for edging and containers.
- Height: 12-15 inches.
Why it is one of the best varieties: The ‘Jewel Mix’ offers a kaleidoscope of colours, making it a favourite for gardeners who want a lively, colourful display. Its compact habit makes it ideal for borders and containers, ensuring a neat and tidy appearance in any garden setting.
4. Tropaeolum majus ‘Peach Melba’
- Colour: Creamy yellow flowers with vibrant red-orange markings in the centre.
- Foliage: Medium green, rounded leaves.
- Growth Habit: Compact, suitable for borders and pots.
- Height: 10-12 inches.
Why it is one of the best varieties: ‘Peach Melba’ stands out for its unique and elegant flower coloring. The creamy yellow petals with red accents add a touch of sophistication to any garden. This variety is perfect for those looking to add a soft, yet striking visual interest to their garden spaces.
5. Tropaeolum majus ‘Whirlybird Series’
- Color: A mix of colours including red, orange, yellow, and salmon.
- Foliage: Light green, rounded leaves.
- Growth Habit: Semi-trailing, ideal for ground cover and hanging baskets.
- Height: 12-14 inches.
Why it is one of the best varieties: The ‘Whirlybird Series’ is known for its unique, upward-facing flowers that make a bold visual impact. The semi-trailing habit makes it good for both ground covers and hanging baskets.
Pinching for bushier growth
To encourage bushy growth, pinch back the growing tips when the plants are about 6-8 inches tall. This technique promotes branching and leads to more blooms.
Support for climbing varieties
Some Nasturtium varieties can climb. If you want your Nasturtiums to grow vertically, provide support like a trellis.
Alternatively, let them spill over from window boxes or hanging baskets for a cascading effect of bright colours.
Deadheading for continuous blooming
Regularly removing dead or faded flowers (deadheading) encourages the plant to produce more blooms. This process prevents energy from being diverted into seed production.
Managing pests and diseases
Nasturtiums are generally resistant to pests and diseases but can sometimes be affected by aphids, caterpillars and snails. You can effectively manage these issues with organic pest control methods, such as handpicking or using insecticidal soap.
Saving seeds for the next season
Nasturtiums produce large seeds that are easy to collect and save. Allow some flowers to mature and form seed pods. Harvest the pods once they turn brown and dry, and store the seeds in a cool, dry place.
Edibility and culinary uses
The flowers and leaves of Nasturtiums are both edible. They have a mild, peppery flavour that can enhance the taste and appearance of salads, sandwiches, and other dishes. This adds to the plant’s appeal, making it not only a feast for the eyes but also for the palate.
FAQs in Relation to How to Grow Nasturtium
Do Nasturtiums need to climb?
Most Nasturtiums have trailing or climbing habits, and they will often scramble over other plants in order to reach sunlight.
However, there are some dwarf varieties of Nasturtium that do not climb. Whether or not a particular variety of Nasturtium needs to climb depends on the plant’s natural growth habit.
Do Nasturtium come back every year?
Nasturtiums are annual plants, meaning they live for one growing season and then die. They do not come back every year.
Do Nasturtiums grow well in pots?
Nasturtiums are one of the easiest flowers to grow and they make a great addition to any garden. They can be grown in pots, containers, or directly in the ground.
Nasturtiums prefer well-drained soil and full sun but will tolerate some shade. To plant Nasturtiums, simply sow the seeds about 12 inch deep in early spring after all danger of frost has passed.
Once the seedlings have emerged, thin them out so that they are about 6 inches apart. Nasturtiums will bloom throughout summer until fall.
Deadhead spent blooms regularly to encourage more flowering.
Do Nasturtiums like sun or shade?
Nasturtiums are plants that can tolerate a wide range of light conditions, from full sun to partial shade. However, they prefer locations that offer some protection from the midday sun.
They will also do well in areas with dappled sunlight throughout the day.
Conclusion
Nasturtiums are well-suited for any gardener, from novice to expert. Their capacity to thrive with minimal care, combined with their vibrant blooms and edible leaves and flowers, makes them an exceptionally rewarding plant to grow. Whether you’re looking for a colourful cascade from a hanging basket or a natural pest repellent for your vegetable patch, Nasturtiums are an excellent choice.
Martin Cole has been an avid plant lover and gardener for more than 20 years and loves to talk and write about gardening. In 2006 he was a finalist in the BBC Gardener of the Year competition. He is a member of the National dahlia Society.
He previously lived in London and Sydney, Australia, where he took a diploma course in Horticultural studies and is now based in North Berwick in Scotland. He founded GardeningStepbyStep.com in 2012. The website is aimed at everybody who loves plants or has been bitten by the gardening bug and wants to know more.
Gardening Step by Step has been cited by Thompson and Morgan, the UK’s largest mail order plant retailer, as a website that publishes expert gardening content.