Nasturtiums reward you in many ways, with edible leaves, flowers and seeds. The leaves are peppery and slightly bitter and make a great addition to a mixed leaf salad. The flower buds and young seeds when pickled in brine are known as ‘poor man’s capers’, with a similar pungent flavour.
The culinary highlight however is the flowers. Fiery in looks and flavour, their vivid colour and striking looks light up any plate. They have a peppery kick, balanced by the sweetness of the nectar in the petals.
Originally from the mountains of South America, this exotic looking plant didn’t take long to be adopted in the UK. It is first mentioned as a garden plant in 1548 and became known as ‘Indian Cress’ because of the similarity in flavour to our native garden cresses.
This means that we can definitely justify its inclusion in our 18th Century walled Kitchen Garden here at Hampton Court Palace, as it had already become a firm favourite by then.
By scattering some nasturtium flowers over your mixed salad you will be emulating a dish that would have been served at the grandest banquets!
Easy to grow
There is another reason why nasturtiums became so popular so quickly – they are really easy to grow. They thrive on poor soil, though they will appreciate a sunny position. They come as climbing or dwarf types and the climbers really will climb or sprawl through anything. The stems will twist around canes, trellis, string or other plants and can climb to over 3m.
The dwarfs are best for pots or small spaces. The variety called ‘Tom Thumb’ is one of the most compact, growing 15-30cm high, but sprawling a bit sideways.
For extra interest, some types have attractive green and white mottled leaves and others have flowers that range from deep red, through orange to pale yellow.
How to grow
You can buy ready grown nasturtium plants in spring, but they are so easy to grow from seed you really should have a go. The seed can be sown directly in the ground or in pots first and then planted out.
Last year we sowed the seed direct in the soil in early May by just scattering it over the surface of the soil and then raking it over to lightly cover the seeds. They will need plenty of water at this stage to make sure that the soil doesn’t dry out whilst germinating. We chose a variety which claimed to be a dwarf type and they made a compact start, but by the end of summer they were making a bid for freedom, slowly romping into the neighbouring beds. Luckily, they are incredibly tolerant of being hacked back – we roughly chopped off anything growing outside its allotted space and it didn’t bat a petal.
The only things that do seem to bother nasturtiums pest wise, are blackfly – small, black insects that feed on the sap of the plant. The best preventative is to have healthy, vigorous plants that will grow through any attack – at least until the ladybirds find the blackfly and deal with them.
If the plant really is being overwhelmed, find a clean spray bottle and mix a very dilute solution of washing up liquid (1 tsp to 2 litres) to wash them off. Weirdly you can’t use this as ‘pesticide’ but it’s OK to wash your plants with it.
Nasturtiums will be killed off by the first frost, but before that they will shed lots of their seeds. These are quite large so they don’t travel far from the parent plant, which makes them easy enough to weed out if you decide you don’t want them next year. However, if you do, you can just leave them there to do their own thing – meaning colourful salads for years to come.