Nasturtiums are scrambling and clambering plants that grow well through existing hedges and on fences, screens and trellis. They’ll also head on up your bean poles and decorate your sweetcorn plantation with their bright, open-faced flowers that are great for attracting bees, butterflies and beneficial predatory insects into the garden. Colours range from yellow and orange to red and a rich deep chocolatey red.
As well as brightening up the garden their leaves and flowers make a decorative, peppery addition to salads. Nasturtiums are annual plants that flower, set seed and die all in one season. In warmer areas these clambering fast growers can turn into bit of a perennial thug, growing on through milder frost-free winters and overpowering small shrubs, hedges and seedling plants. Nasturtiums will be killed by frost and so they don’t pose such an invasive threat in cooler parts of the country. Nasturtiums are particularly handy around the edges of the vegetable garden or planted in beds to grow as decoration on wigwams of bamboo canes. In addition to attracting beneficial insects, nasturtiums are often colonized by black aphids – especially yellow flowered varieties - and cabbage white caterpillars so you can plants them as decoy plants to draw pests away from your food plants and deal with any infestations by ripping up affected plants and destroying them.
Companions Radish, cabbage, kohlrabi, broccoli, under-planting for fruit trees.
Alaska red flowers and green and white variegated leaves
Black Velvet chocolatey red flowers good in pots and hanging baskets or as low cover in beds
Empress of India bright red flowers, dwarf clump forming variety
Peach Melba creamy yellow flowers splashed with red
Sow or plant in early spring and summer countrywide.
Nasturtiums grow well in full sun as well as partial shade. They grow well in conatiners.
Nasturtiums are not all that particular and will grow well in most garden soils. They flower best on poor soils.
Soak seeds overnight to improve germination.
Sow nasturtium seeds in spring. Nasturtiums don’t like any disturbance to their roots so its best to sow them straight into the garden. If you are sowing them indoors to get a head start on the warmer spring weather that is hopefully just around the corner then best to sow into peat pots that can then be planted out without disturbance to roots. Sow seeds a finger-tip deep in pots filled with seed compost or directly into the garden. If sowing directly into the garden thin seedlings so that plants end up with around two to three hands’ lengths between them.
When your pot-sown seedlings are about a finger’s length in height and the weather has settled and is reliably warm and sunny, plant seedlings out in the garden. I usually dot them around the vegetable garden on the fringes making sure they are not going where they’ll overpower anything.
Water young seedlings in dry periods. Once they are established and starting to grow you shouldn’t need to continue with watering unless weather is persistently dry and young plants show signs of wilting. Plants should find their own way up through any plants or supports you want them to grow on. Don’t feed nasturtiums or you’ll get loads of foliage at the expense of flowers.
All parts of a nasturtium are edible. The flowers and leaves can be used in salads and the seeds can be pickled – they are a bit like capers. Using the seeds like this is a good way of containing their general sprawl in warmer areas where they are not killed off by winter frosts.