They are both perennial vegetables, but that’s about all they have in common. The Jerusalem artichoke is completely hardy, and spring-planted tubers can give a tenfold increase by the following autumn. The name is nothing to do with the Holy Land, but is derived from the Italian word girasole, meaning ‘sunflower’. The plant grows like a sunflower – to which it is closely related – and it needs hot summers to flower well, although this has little bearing on the crop.
Jerusalem artichokes are easily cultivated in ordinary soil. Plant the tubers in late February or early March (using shop-bought ones if you prefer). Set them about 5in deep and 15in apart in rows 3ft apart. Small tubers are the best for planting, providing they have at least one eye. Don’t feed or manure the crop because that will encourage the growth of foliage at the expense of tubers. Lift tubers as needed between October and spring.
You need green fingers to grow good globe artichokes, especially if you try your hand at raising them from seed rather than planting rooted side growths or suckers in the spring.
The edible, fleshy scale-covered flower heads are their main attraction, and mature plants grow up to 5ft high. As a decorative bonus, the large, silvery-grey leaves look good in a roomy border.
Like the Jerusalem artichoke, the globe artichoke appreciates full sun, but it dislikes heavy clay soils. Find a well-drained spot and dig in lots of peat or garden compost before planting. It also dislikes the cold, and even in mild areas a thick winter covering of ashes, strawy manure or bracken is advisable.