Ah, the simple joy of nasturtiums: surely no one has ever failed with them, with their easygoing nature, and their relentless desire to flower their socks off, all for the price of a packet of seeds. They can be dismissed as ordinary, but if you want to cover up something unsightly or just spend a summer cheered by their frilly flowers, now is the time to sow them.
Nasturtiums belong to the genus Tropaeolum found in South America. The two most popular species – the semi-trailing bush, orange flowering T. minus and the taller, sprawling, red flowering T. majus – come from Peru, brought to Europe by Spanish conquistadors and Dutch explorers respectively. They did a seed swap and the result is a smorgasbord of tropical colours in between.
You just have to decide which side of tasteful you sit. There’s the bluish-green leaves and deep, velvet red of ‘Empress of India’ or the dwarf ‘Princess of India’, the dusky pink tones of ‘Ladybird Rose’ or the palest cream ‘Milkmaid’.
The other end of the scale is ‘Alaska’. There’s nothing tasteful about it and thus I have a soft spot for it. The flowers, in garish shades of orange, orange-red and scarlet, sit alongside leaves that look like they have been splattered in white paint. The tiniest of its leaves make a salad look surprisingly sophisticated and add a watercress pepperiness.
If you want to go one further, try Mashua, the perennial nasturtium, T. tuberosum. It has a pretty, scalloped dark, bluish-green leaf and, if the summer is hot enough, a tubular orange red flower and then, in autumn, a tuber that is best described as Jabba the Hutt in shape. After repeated experiments I still can’t quite fathom why you’d want to eat it, but you can. I grow mine in pots and use it as a temporary filler for evergreen wall climbers that are still establishing.
If you want to cover a wall or fence, try T. peregrinum, the canary bird creeper, with pale yellow frilled flowers and deeply lobed leaves; or T. speciosum, the flame nasturtium, which has blue-green leaves and scarlet flowers. T. peregrinum is perennial, but not frost hardy and it will die back over our winter; T. speciosum does best with cool roots and won’t mind partial shade.
All nasturtiums do best in poorer soils and can be sown now direct into pots or the ground. Soils too rich in organic matter will produce all leaf and no flowers and this lush growth sometimes results in an aphid attack. An old trick was to use the floor sweepings to ensure the soil was poor enough.
