Nasturtium plants are a must-have in Australian gardens with their vibrant blooms and peppery leaves.
Not only do they bring colour and life to your vegetable garden, but they are also incredibly versatile and easy to grow.
Whether you’re in the humid north, the mild south, or anywhere in between, here’s how to cultivate nasturtiums in Australia.
Types of Nasturtium
There are two main types of nasturtium: trailing or climbing nasturtium and bush nasturtium.
Then there are perennial variants, such as the Chilean nasturtium, Canary Creeper and Flame nasturtium.
Trailing or Climbing Nasturtium (Tropaeolum majus)
Trailing nasturtiums (also known as climbing nasturtiums) are perfect for covering ground or spilling beautifully over walls and hanging baskets.
Jewel of Africa
The Jewel of Africa nasturtium features variegated leaves with a mix of red, orange, yellow, and cream flowers.
It can climb up to 2 metres under the right conditions, adding a wild yet elegant touch to garden trellises and fences.
The variegation in the foliage, combined with the wide colour range of its blooms, makes it a standout choice for adding texture and colour to any garden space.
Alaska Mix
The Alaska Mix nasturtium is also called Indian Cress or Monk’s Cress — not to be confused with watercress, a leafy green vegetable scientifically called Nasturtium officinale. Plants, right?
This flowering plant stands out with its striking variegated foliage, which contrasts beautifully with its bright flowers in shades of yellow, orange, and red.
Alaska Nasturtium is excellent for adding texture and colour to hanging baskets or as ground cover.
Moonlight
Moonlight nasturtium is a unique trailing variety with its pale yellow flowers that seem to glow in the garden.
As a vigorous climber, it is ideal for softening garden structures with a cascade of light-reflecting blooms.
The Moonlight nasturtium’s subtle flower colour can blend with many garden palettes, offering versatility in design.
Bush or Dwarf Nasturtium (Tropaeolum minus)
Bush type nasturtium plants are more compact, making them ideal for small gardens or as border plants.
Empress of India
The Empress of India boasts deep crimson flowers with dark blue-green foliage.
Its bushy, compact form is ideal for defining garden paths or adding depth to container plantings.
The rich colour of the Empress of India’s blooms makes it a favourite for gardeners seeking a bold colour statement.
Peach Melba
Peach melba nasturtium flowers offer a softer palette with unique creamy yellow blossoms.
Each petal of this lovely flowering plant is detailed with a raspberry splash.
Its dwarf habit and delicate appearance make it a charming addition to small spaces and patio containers.
Tom Thumb Black Velvet
The Tom Thumb Black Velvet is a bush nasturtium variety renowned for its deep, velvety maroon flowers that appear almost black.
This compact flowering plant grows up to 30 cm tall and wide, making it an excellent choice for small gardens, borders and containers.
Its dwarf habit ensures it remains contained, perfect for those looking to maintain a tidy yet bold garden display.
Whirlybird Mix
The Whirlybird Mix (or Whirly-bird Mixed) is known for its semi-double flowers that rise above the foliage in a mix of vibrant colours.
It’s a bushy nasturtium variety that doesn’t trail, making it perfect for creating dense, colourful borders or as a cheerful ground cover.
Perennial Nasturtium
If you’re looking for blooms that grace your garden every year, perennial nasturtiums are a fantastic choice.
These varieties fall under the bush and trailing categories with the additional ability to bloom each year without having to be replanted.
Canary Creeper (Tropaeolum peregrinum)
The Canary Creeper enchants with its frilly, yellow flowers that resemble canaries in flight.
This climber is perfect for adding a touch of whimsy and light to garden trellises or fences.
Chilean Nasturtium (Tropaeolum speciosum)
The Chilean Nasturtium is a true gem with its fiery red flowers that seem to ignite garden settings with colour.
It thrives in cooler climates, climbing eagerly over supports or through shrubbery.
The Chilean Nasturtium adds a bold splash of red to the garden and can attract beneficial insects to your garden.
Flame Nasturtium (Tropaeolum ciliatum)
The Flame Nasturtium offers bright orange flowers akin to flames against its green foliage.
It’s a vigorous climber, perfect for creating a dramatic focal point in the garden.
The unique flower shape and colour of the Flame Nasturtium make it an excellent choice for gardeners looking to add a touch of the exotic to their landscape.
When To Plant Nasturtiums In Australia
The best time to plant nasturtium seeds in Australia is from late winter to early spring in cooler regions, ensuring they’re established before summer.
In tropical and subtropical areas, planting in spring can give nasturtium seeds a head start before the wet season.
Where To Plant Nasturtium
Nasturtiums thrive in full sun but can tolerate partial shade, making them versatile for different garden spots.
The best place to plant nasturtiums is in a garden bed with well-drained soil.
Another option is to put your nasturtium plant along fences or walls so that climbing types can cover unsightly areas.
You can also plant trailing nasturtiums in hanging baskets, where their flowers can cascade down.
Growing Nasturtiums From Seed
Nasturtium seeds are large and easy to handle, making them perfect for direct sowing into gardens or pots.
Plant the nasturtium seeds in well-drained soil about 1 to 2 cm deep after the last frost or when the soil has warmed up.
Nasturtiums prefer a sunny spot but can tolerate partial shade, where they’ll produce more leaves than flowers.
Water the seeds after planting and keep the soil moist until germination, which is typically within 7 to 10 days.
Nasturtiums are not fussy about soil quality; they thrive in less fertile soil, which encourages more blooms rather than lush foliage.
As they grow, thin the seedlings to about 25 to 30 cm apart to give each plant room to spread.
Growing Nasturtiums From Cuttings
Propagating nasturtiums from cuttings is a less common but equally effective method to multiply your nasturtium plants.
This is useful if you want to replicate the exact characteristics of a particular plant or if you want to extend the growing season of your nasturtiums.
You can take cuttings in late summer for overwintering indoors. (Gardener’s note: Overwintering simply means living through the winter.)
Select a healthy, non-flowering stem and cut a segment about 10 to 15 cm long.
Remove the lower leaves to expose a few nodes; roots will develop from these points.
You can either plant the cuttings in peat pots filled with moist, well-draining potting mix, or place them in water until roots form, which usually takes a couple of weeks.
Ensure the cutting is kept in a warm, bright location out of direct sunlight to encourage rooting.
How To Propagate Nasturtium
Propagating nasturtium can be achieved through seeds and cuttings, allowing gardeners flexibility in expanding their nasturtium collection.
Seeds are the most straightforward method of propagation; you can collect nasturtium seeds from dried pods of existing plants at the end of the season and store them in a cool, dry place until planting time.
This approach allows for the easy sharing of seeds and encourages the natural cycle of growth and renewal in the garden.
On the other hand, cuttings offer a rapid multiplication method, ideal for cloning a specific plant with desirable traits.
Nasturtium Companion Planting
Add brief intro sentence here about the value of companion planting nasturtium
Tomatoes
Nasturtiums and tomatoes are excellent companions.
Nasturtiums repel common pests like aphids, whiteflies, and tomato hornworms, potentially reducing the need for chemical pesticides.
Their sprawling nature also helps to cover the ground, keeping the soil moist and cool, which tomatoes appreciate.
Cucumbers
Thanks to their strong scent, planting nasturtiums with cucumbers can help repel cucumber beetles and other pests.
Additionally, nasturtiums attract pollinators, which benefits the fruit set on cucumbers.
The shade provided by cucumber plants, in turn, can help nasturtiums thrive in hot climates by offering protection from the intense midday sun.
Squash and Pumpkins
Nasturtiums act as a trap crop for squash bugs and beetles when planted near squash and pumpkins.
Their bright flowers repel these pests from the squash plants, reducing damage.
The ground cover provided by nasturtiums also helps maintain soil moisture, which is beneficial for squash and pumpkin growth.
Fruit Trees
Underplanting nasturtiums around fruit trees can attract beneficial insects that pollinate the trees and control pests.
Their ability to repel certain insects can also protect the health of young fruit trees, including apple, pear, peach and cherry trees.
The vibrant flowers of nasturtiums add to the aesthetic value of an orchard while supporting the ecosystem’s health.
Radishes
Nasturtiums planted alongside radishes can improve the radishes’ flavour and growth.
The peppery scent of nasturtium leaves may deter pests that target radish plants, while their flowers attract pollinators, enhancing overall garden biodiversity.
What Not To Plant With Nasturtiums
Brassicas (cabbage, mustard plant)
Nasturtiums might attract pests like aphids and cabbage white butterflies, which could pose a problem for plants in the Brassica family, such as cabbage, kale, and broccoli.
While they’re great for luring aphids away from other plants, their proximity to brassicas might inadvertently draw these pests towards them.
Beans and Peas
Nasturtiums have a strong growth habit that can overwhelm the more delicate structures of beans and peas.
Their vigorous vines may compete for support structures or directly intertwine, making it difficult for the legumes to climb.
Additionally, the dense ground cover formed by nasturtiums might impede the growth of these plants by overshadowing them or competing for soil nutrients and water.
Some Herbs
Herbs that prefer drier soil, such as rosemary, thyme, and lavender, might not fare well when planted beside or near nasturtiums.
Nasturtiums often require more water, and their preference for moist conditions could lead to root rot or other issues in these drought-tolerant herbs.
Nasturtium Benefits
Nasturtium Can Attract Beneficial Insects
Nasturtiums are excellent at attracting beneficial insects to the garden, including pollinators like bees and butterflies.
Their bright flowers add colour and vibrancy and are a natural lure for these helpful creatures.
Planting nasturtiums near vegetable beds or fruit-bearing plants can significantly increase their yield by ensuring thorough pollination.
Nasturtium Can Repel Pests
One of the most valued aspects of nasturtiums in companion planting is their ability to repel various pests.
Aphids are particularly drawn to nasturtiums over other plants, making them an ideal sacrificial crop that can protect more vulnerable plants.
This characteristic makes nasturtiums a strategic companion for a wide range of plants, including roses and vegetable crops like tomatoes and cucumbers, by serving as a natural pest deterrent.
Nasturtium Can Improve Growth and Flavour
Nasturtiums have been observed to improve the growth and flavour of other plants, especially when planted near cucumbers, radishes, and various fruit trees.
The exact mechanism isn’t fully understood, but it’s thought that the presence of nasturtiums may stimulate the growth of these plants or enhance soil conditions in a way that benefits neighbouring crops.
Nasturtium is An Edible Flowering Plant
Nasturtiums are not only ornamental but also entirely edible, making them a versatile addition to the kitchen.
The leaves and flowers have a peppery taste similar to arugula, adding a unique flavour to salads, sandwiches, and garnishes.
Nasturtium seeds can also be pickled to create a caper-like condiment, offering a sustainable way to enjoy every part of the plant.
Nasturtium Has Medicinal Uses
Historically, nasturtiums have been used for their medicinal properties and natural antibiotic effects.
The high vitamin C content in their leaves and flowers can support the immune system.
At the same time, their natural antibacterial properties have been utilised in traditional remedies to treat minor scrapes and cuts.
The plant’s unique compounds may also offer mild antifungal and antimicrobial benefits.
Nasturtium Problems
Susceptibility to Pests
While nasturtiums are excellent at attracting beneficial insects, they can also become a magnet for aphids and other pests.
This susceptibility means that while they can protect other plants by drawing pests away, they may require monitoring and management to prevent infestations.
Natural remedies can help control these pests without resorting to harsh chemicals. These may include spraying with soapy water or introducing beneficial insects like ladybugs.
Vulnerability to Diseases
Nasturtiums can be prone to fungal diseases, such as powdery mildew, especially in humid or wet conditions.
To prevent these issues, provide good air circulation around the plants and avoid overhead watering.
Regularly removing affected leaves and ensuring the plants are not too densely packed can also help maintain their health and vigour.
Common Questions About Growing Nasturtiums
Do nasturtiums come back every year in Australia?
Yes, nasturtiums come back every year in the warmer parts of Australia.
Can you eat nasturtium leaves?
Yes! You can eat the leaves, flowers and immature seed pods.
Nasturtium leaves have a slightly peppery taste, which can elevate the flavour of any salad.
When do nasturtiums flower?
Nasturtiums typically start flowering about eight weeks after planting.
They can continue to bloom from early spring to autumn.
Do nasturtiums flower all year?
Nasturtiums can flower most of the year in the warmest parts of Australia.
They have a better chance of doing so if they are watered regularly and deadheaded to encourage more blooms.
