Grower’s Corner – Jerusalem Artichokes
Jerusalem Artichokes are related to the sunflower and can reach over ten feet tall. It’s not an artichoke and it doesn’t come from Jerusalem! The edible part of this member of the sunflower family is actually the tuber or swollen end of an underground stem, which in some respects resembles a potato. However, unlike most starchy vegetables, the principal carbohydrate contained in the tubers is insulin, rather than starch, which makes them much easier for diabetics to digest. The name is a corruption of the Italian girasole (turns to the sun) and the plant actually originates in America where it is also called the sun choke. The new Fuseau variety produces larger, longer and smoother tubers than the common 'knobbly' variety, making them much easier to prepare for cooking (you may have seen them on TV cooking programmes looking nothing like the kind you see in posh greengrocers) and more productive per plant. The Jerusalem artichoke has one quality that doesn’t usually get mentioned on those celebrity chef programmes: it’s a potent wind-producer, so this is a tuber to serve for dinner when you are with relatives or close friends, not trying to impress the boss or a new love interest!
The good news is that the Jerusalem Artichoke will thrive in any soil type providing it is not too acidic or waterlogged and this is a great plant for breaking up heavy soil so it’s an ideal crop for new vegetable gardens and those who have taken over a neglected allotment. More good news: no feeding or manuring is required – in fact it’s a bad idea, as it would encourage the growth of foliage at the expense of the tubers.
Plant the seedling tubers six inches deep and eighteen inches apart between March and April depending on your local conditions. Some support may be required, and that can take the form of stretching wire between posts at a height of about six feet. Once established, Jerusalem Artichokes actually make a good windbreak in their own right, and can protect other crops from the ravages of summer wind damage right through to November.
Although the flowers are pretty, like small sunflowers, you need to remove flower heads as they appear to promote tuberous growth. You can start harvesting Jerusalem Artichokes after they flower but they’ll have peak taste after the first killing frost, so sometime between October and November, when foliage turns brown, cut it down to about a foot above the ground and lift the tubers as required. Cover stem bases with soil or straw in severe weather, to protect tubers still in the ground.
If you don’t remove all the tubers from the ground at the end of the season they will return as weeds! It’s a tenacious and fast-growing perennial and can become a weed problem. Since it is nearly impossible to harvest all the tubers in a field or garden, there will be a large number of volunteer plants the following spring which should be destroyed before they can set tubers in August or they will take over your plot!
The skin of Jerusalem artichokes is very thin and care should be taken in harvesting and handling them to avoid skinning, cutting and bruising the tubers.
Jerusalem Artichoke photographs by Andyrob and author’s own, used under a creative commons attribution licence