Nasturtiums are vibrant, easy-to-grow flowers that can add a splash of colour to your garden. Not only are they beautiful, but they’re also edible, with peppery leaves and flowers that can be a unique addition to salads. If you’re in Australia and looking to grow nasturtiums from seeds, follow these simple steps to success.
A History of Nasturtiums
Nasturtiums, known scientifically as Tropaeolum majus, are vibrant flowers with a fascinating history. They originated in South America, specifically the Andes region and have been cultivated for centuries by indigenous peoples.
Spanish explorers introduced them to Europe in the 16th century. The name “nasturtium” comes from the Latin words “nasus” (nose) and “tortus” (twisted), referring to the pungent smell and twisted shape of the plant’s seed pods.
Although originally applied to watercress, nasturtiums also belong to the Brassicaceae family. Both the flowers and leaves of nasturtiums are edible with a peppery flavour similar to watercress. They are often used in salads and as a substitute for capers.
Nasturtiums also have a history of medicinal use, being used to treat respiratory infections, urinary tract infections, and scurvy due to their high vitamin C content.
In the language of flowers, nasturtiums symbolise patriotism and conquest, with their bright colours associated with the sun and vitality. Nasturtiums are also valued in gardening for their ability to repel pests like aphids, whiteflies and cucumber beetles, making them a popular choice for companion planting.
How to Grow Nasturtiums from Seeds: A Step-by-Step Guide
Step 1: Choose Your Seeds & Prepare Your Soil
Purchase high-quality nasturtium seeds, before preparing your soil. When choosing a place in your garden to sow your nasturtium seeds, ensure the spot receive at least 6 hours of sunlight daily for optimal growth and flowering. Nasturtiums love full sun but can also tolerate partial shade.
Nasturtiums also thrive in well-draining soil that is rich in organic matter. If you find the soil lacking in nutrients, work compost or well-rotted manure into the soil to improve its fertility.
Step 2: Plant Your Seeds & Water Regularly
In Australia, the best time to grow nasturtiums from seeds depends on the climate and region. Generally, nasturtiums can be sown from late winter to early summer in most parts of Australia. This timing allows them to establish before the heat of summer or the cooler temperatures of winter arrive.
In warmer regions, such as northern Australia, nasturtium seeds can be sown in late autumn to early winter or in early spring. In cooler regions, such as southern Australia, it’s best to wait until after the last frost in spring to sow nasturtium seeds.
Nasturtiums are quite versatile and can tolerate a range of conditions, but they prefer well-drained soil and full sun. It’s also a good idea to sow the seeds directly into the garden bed, as nasturtiums don’t transplant well. Plant the seeds about 2-3cm deep and space them 20-30cm apart.
Water the seeds well after planting. Keep the soil moist but not waterlogged, then once established, water the plants deeply once a week or more frequently during hot, dry periods.
Step 3: Support Climbing Varieties
If you’re growing climbing varieties of nasturtiums, provide a trellis or other support for them to climb on. This will help them grow upward and prevent them from sprawling on the ground.
Step 4: Mulch Around Plants
Mulching around your nasturtiums can help retain moisture, suppress weeds, and improve soil fertility. Use organic mulch such as straw or compost.
Step 5: Harvest Flowers and Leaves
Nasturtium flowers and leaves are edible and can be harvested throughout the growing season. Use them fresh in salads or as a garnish. Discover 10 unique ways to cook with nasturtiums here.
Step 6: Watch for Pests and Diseases
Nasturtiums are generally pest and disease resistant, but they can occasionally be affected by aphids or caterpillars. Remove pests by hand or use an organic insecticidal soap if necessary.
Growing nasturtiums from seeds in Australia is a rewarding experience that can provide you with beautiful flowers and delicious, edible greens. With proper care and by following these simple steps, your nasturtiums should bloom profusely throughout the growing season, adding beauty and flavour to your garden. Enjoy their bright blooms and peppery leaves and consider saving seeds for next year’s garden.
