Out with the shears, and off with their heads – now’s the time to get to grips with Jerusalem artichokes.
This statuesque plant isn’t actually an artichoke as we know it – it’s a relative of the sunflower and it’s a true native of North America where it is more commonly known as the sunchoke.
It was introduced to France in the 17th century by Samuel de Champlain, and Europe soon became a major grower. The name is supposedly from girasole (Italian for sunflower).
Although it boasts attractive yellow flowers perched on 3m (10ft) stems, it’s grown more for its below-ground tubers which can be cooked or eaten raw.
You can usually buy them in March and April from a garden centre or via the internet. Plant them a good six inches deep in well-prepared soil, with the tubers spaced a foot apart because they need plenty of space in which to grow. In fact, you can kill two birds with one stone by using the perennial as a windbreak or screen.
Alternatively, the tubers can also be grown in a large tubs filled with good compost.
When stems reach a foot or so in height, draw soil around them to help stabilise plants as they grow. In midsummer, cut back the stems (including the flowerheads) to five feet in height to stop the plants from being damaged by wind.
Jerusalem artichokes grow tall – hence their ability to act as a screen – but may need some support in very exposed and windy sites. Otherwise, you risk losing them.
When the foliage starts to turn yellow in autumn, prune to leave three-inch stumps above ground level. Place the prunings over plants to keep the soil warm and aid the lifting of tubers in frosty weather.
But it’s probably because Jerusalem artichokes are easy to cultivate that people are tempted to leave them alone, to let them grow as they will. But year on year, the quality of the edible tubers degrades unless the plants are dug up and replanted in fertile soil.
And here’s the rub – even a small piece of tuber left in the ground will spring into growth, so unless you remove every vestige of the plant, you’ll find them springing up like weeds. That’s why some gardeners grow them in containers.
The flesh of the artichoke has been described as slightly waxy, sweet, nutty and distinctive. I don’t like it much – so I don’t grow them.