RHS Growing Guides
How to grow Jerusalem artichokes
Our detailed growing guide will help you with each step in successfully growing Jerusalem artichokes.
Getting Started
Jerusalem artichokes are easy to grow and need little maintenance. They are tall plants that produce a prolific crop of underground
Jerusalem artichokes provide a bounty of buried treasure, yet are low maintenance to grow
Despite their name, Jerusalem artichokes aren’t from the Middle East, but from North America, and aren’t related to globe artichokes. Instead, they’re a relative of the sunflower and produce characteristic yellow flowers at the top of their tall stems. The name Jerusalem is thought to be derived from the Italian for sunflower, girasole. They are often known as sunchokes in the US, although they will also crop in partial shade.
As Jerusalem artichokes are relatively expensive to buy in the shops, but extremely easy to grow, they’re a useful and cost-effective crop. They can be dug up over a long period, after many other crops have finished, providing valuable winter harvests.
Month by Month
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| Harvest |
Choosing
Select large, firm tubers to plant, ideally as smooth as possible so the crop will be easy to clean when harvested. Small, knobbly tubers can be time-consuming to prepare. It’s worth taking the trouble to buy good-quality tubers to start with if you want to continue growing the crop for years. Then you can simply replant some of your harvested tubers every year, selecting large, firm, smooth ones, or just leave some in the ground to re-grow.
Recommended Varieties
A shorter variety, only about 120cm tall, with long, smooth, white-fleshed tubers.
Large, smooth-skinned tubers that are easy to peel. Plants reach 2m tall or more.
Planting
Choose large, smooth tubers and plant them in the ground or in containers
These sunflower relatives can grow very tall (up to 3m/10ft), so when choosing a planting site, make sure they won’t cause problems overshadowing other crops nearby. They may need support in exposed locations, but can act as a useful windbreak if you plant several rows. Choose your planting site with the longer term in mind too, as the plants may well reappear the following year. Any tubers left in the ground (by accident or design) are likely to re-grow in spring, so artichokes can be hard to get rid of if you no longer want them in that spot. Although, on the positive side, this means you don’t have to keep buying new tubers to plant every year.
Planting in the ground
Before planting, enrich the soil with plenty of home-made garden compost. Then plant the tubers 15cm (6in) deep and 30cm (1ft) apart, in rows or staggered rows or in blocks. Allow 1.5m (5ft) between the rows. To produce more plants, you can cut large tubers into two or three pieces about the size of a hen’s egg – just make sure there is at least one bud on each piece. Water them in well after planting.
Planting in containers
If your soil is too wet for planting in late winter or spring, you can start the tubers off in pots outdoors. Then transplant the young plants into the ground once your soil is no longer waterlogged. See our guide to transplanting.
Alternatively, you can grow the crop entirely in a large pot. This should be at least 45cm (18in) wide and deep, to accommodate one or two tubers, planted 15cm (6in) deep. Use peat-free multi-purpose compost. Place the container in a sheltered spot, in sun or partial shade. Bear in mind that plants in containers need regular watering, especially in hot weather, and are likely to produce a smaller crop than in the ground. However, containers have the advantage that the plants can’t spread beyond their bounds, which is possible in the ground if lots of tubers are left unharvested.
Plant Care
Jerusalem artichokes are strong, vigorous plants and need little maintenance apart from watering in dry weather and tall supports unless they’re in a sheltered spot.
Watering
Water regularly during dry spells in summer, to ensure the tubers swell. Lack of water may lead to smaller, more knobbly tubers that are fiddly to prepare in the kitchen. Plants in containers need regular watering throughout the growing season.
Mulching
Mulch the soil surface with garden compost to help hold moisture in the ground, especially in fast-draining sandy soil.
Supporting
When the stems are 30cm (1ft) tall, draw up a mound of soil around the base, about 15cm (6in) high, to help stabilise the plants as they grow. In windy sites, insert tall bamboo canes around the outside of plantings, linked together with twine. Good support helps to prevent wind-rock, which can loosen the tubers in the ground, hindering growth or even leading to rotting. Supporting them like this will also help to keep the plants tidy.
Alternatively, you can cut the stems down to 1.5m (5ft) in late summer (although you’ll lose the flowers), so they won’t be buffeted by the wind, which can loosen the roots or topple the stems. Don’t reduce their height any more than that though, as it could lead to a smaller crop of tubers. Plants in containers, in particular, will benefit from being cut back, to reduce the risk of the pot being blown over.
Removing flowers
These sunflower relatives produce small, cheery yellow blooms at the tops of their tall stems in autumn, adding welcome colour to the veg plot. But you may prefer to remove the flowers, to encourage plants put all their energy into swelling their tubers.
Overwintering
Tubers are hardy and can be left in the ground all winter, for harvesting whenever needed. In colder regions, cover the ground with a thick mulch, or other insulation such as cardboard, to deter freezing, so you can still dig them up during icy spells. The tubers don’t store well indoors, so are best kept in the ground until needed.
Propagating
Save some of the best, smoothest tubers from your harvest and replant them, for a crop the following year. Alternatively, just leave a few in the ground if you’re happy to let them continue growing in the same spot.
Pruning and Training
Cut back any tall stems that get broken by the wind, just below the point of damage. On exposed sites, it’s best to prune all stems down to 1.5m (5ft) in late summer, to prevent wind damage. This means you won’t get any flowers, but plants will then put all their energy into their tubers, so you may get a larger crop.
When the leaves start to turn yellow in autumn, cut down the stems to stumps about 8cm (3in) tall. Leave these as useful indicators of where the tubers are. Place the prunings over the stumps to keep the soil warm and make it easier to dig up the tubers in frosty weather.
Harvesting
Use your home-grown artichokes in a similar way to potatoes – steamed, roasted or baked
The tubers have a nutty flavour and can be used in the same way as potatoes. Depending on how smooth they are, you can peel them before or after cooking, or, if thin skinned, not at all. Jerusalem artichokes contain a carbohydrate that isn’t broken down during digestion and can cause wind, especially if you eat a lot at one time. Try eating small quantities to start with, to see how you react. Cooking them in lemon juice may prevent this side-effect, as may harvesting late in the season – it’s worth experimenting to see what works best for you.
Problems
Jerusalem artichokes are healthy, robust plants that rarely suffer serious problems. Slugs and snails may nibble new shoots, but don’t cause significant damage to older growth. They may also eat into the tubers, especially over winter.
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