What are Jerusalem artichokes?
Jerusalem artichokes, officially Helianthus tuberosus, are sweet tubers that were introduced to Europe from North America in the 17th century. As their Latin name suggests, Jerusalem artichokes are related to the sunflower family.
The tuber's skin ranges from beige to purple in color. Depending on the variety, the flesh can be white, brown, yellow, or reddish. Their shape is generally irregular and elongated, though some varieties produce rounder tubers. The plant can grow between 1.5 and 3 meters tall.
Unlike potatoes, Jerusalem artichokes are hardy. They fall under the category of "forgotten vegetables" but are now regaining popularity among gardeners and farmers alike.
How to grow Jerusalem artichokes?
Jerusalem artichokes are grown from tubers, not seeds. You can plant them either directly in the ground or in a pot. With just two plants, you'll have plenty of harvest for a household of 2 to 4 people.
It is best not to grow Jerusalem artichokes in the same spot year after year. While it may be tempting—since any leftover tubers will sprout new plants the next year—rot can occur if you don't rotate them. Ideally, plant them in the same spot only once every four years to avoid stem and root rot.
Cucumber vines and bush beans make great companions for Jerusalem artichokes.
What should you not plant next to Jerusalem artichokes? Avoid planting potatoes nearby, as the two will compete underground. Also, do not plant them in areas where sunflowers grew the previous year, since they are closely related.
If you're growing them in pots, and you refresh the soil annually, you'll avoid these issues altogether.
Choose healthy, intact tubers for planting. You can speed up root growth by placing the tubers in a dish of water on a windowsill for a few days before planting.
How far apart should you plant Jerusalem artichokes?
Plant the tubers 15 cm deep and 30 to 40 cm apart if you're planting them in the ground. When planting multiple rows, leave 75 cm between each row. If you're planting already sprouted plants, follow the same spacing. The green parts of the plant will grow above ground.
If you want to plant them in a pot, three tubers per container should suffice. Choose the sunniest spot on your patio for best results. Use a pot or container with good drainage, as these tubers don't like waterlogged soil. A shorter variety of the plant is ideal for container gardening, as it won't topple over easily in storms or strong winds.
What is the ideal soil for Jerusalem artichokes?
Jerusalem artichokes thrive in light, well-drained soil with a neutral pH. Like sweet potatoes, they are prone to rot in wet or poorly drained soil. If the roots are given enough space, they can grow up to 1 meter deep.
For container gardening, use a mix of garden soil, compost, and potting soil.
When to plant Jerusalem artichokes?
Jerusalem artichoke tubers can be planted between November and mid-April. They will sprout in the spring.
If you are planting sprouted plants, aim to get them in the ground between early April and mid-May.
How do Jerusalem artichokes grow?
Jerusalem artichokes are very easy to grow. They are not picky about soil conditions but need adequate water for good tuber development. However, overly wet soil can have a negative impact. They grow best in well-aerated soil and prefer a sunny location, though partial shade will also work.
Each tuber produces one or more stems. Once the first shoots appear, you can mound the soil around the plant, which helps improve tuber formation and keeps the tubers well-protected underground.
Jerusalem artichokes rarely bloom, but this isn't important for tuber formation. Even without flowering, you'll get plenty of tubers. Only the earliest varieties tend to bloom in our climate. If your plants do bloom, you can use the flowers as cut flowers. They resemble sunflowers, but in a smaller form. Flowerless plants will produce more tubers.
Since Jerusalem artichokes can grow up to 3 meters tall, it’s important to plant them in a sheltered area or tie them up when they reach full height. Otherwise, they may fall or break during storms or heavy winds.
Fertilizing Jerusalem artichokes?
Jerusalem artichokes generally do not need to be fertilized if you're growing them as a hobby. If you have well-aerated soil with active soil life, the microorganisms will provide the plants with the nutrients they need. Mulching with some compost is always a good idea, as it supports soil life.
Harvesting Jerusalem artichokes
Jerusalem artichokes planted in the fall or early spring can be harvested in October. If you plant them in April, it’s best to wait until late November to harvest. The longer you wait, the larger the tubers will grow.
If you leave them in the ground until after the first frost, they will taste sweeter. This is because starches in the tubers are converted to sugars after exposure to cold weather.
You don't need to wait for the foliage to die back before harvesting the tubers. The easiest way to harvest is to first trim the foliage with pruning shears, then use a fork to dig up the tubers. It's best to dig up the whole clump at once to avoid damaging the tubers.
You can leave Jerusalem artichokes in the ground all winter and harvest them as needed.
Storing Jerusalem artichokes
Jerusalem artichokes are frost-hardy, so they can be stored in the ground. However, it’s advisable to dig them up, as some tubers may rot. After harvesting, you can store them in sand in a different location, covered with straw and plastic. Any damage to the tubers during harvesting can lead to rot during storage.
It’s not recommended to store them uncovered in a shed or another cool place, as they will dry out quickly.
I personally store the tubers in layers in a box, with plenty of dry sand between each layer to prevent them from drying out.
Jerusalem artichokes spreading
Jerusalem artichokes can indeed spread rapidly! If you leave just a few tubers behind during harvesting, they’ll sprout into new plants the following year. While this can be convenient, to avoid root rot it’s best to remove or replant the sprouting plants in a new area.
You can control their spread by growing them in a large container. However, the yield in open ground is usually greater than in pots, so you’ll have to take that into account.
What are Jerusalem artichokes good for?
Jerusalem artichokes are a starchy vegetable, containing about 80 kcal per 100 grams. They are considered a healthy vegetable because they provide complex carbohydrates with plenty of fiber. One of the key compounds in Jerusalem artichokes is inulin, a type of dietary fiber that converts to fructose when cooked, giving the tubers a sweet taste. If eaten raw, the inulin remains intact, offering additional digestive benefits and helping stabilize blood sugar levels. This can be especially beneficial for those with constipation or diabetes.
Jerusalem artichokes also contain calcium, iron, silicon, and sodium, which have a positive effect on conditions such as gout and rheumatism.
Diseases affecting Jerusalem artichokes
Powdery mildew
Jerusalem artichokes, like sunflowers, are susceptible to powdery mildew. This appears as white mold on the leaves,...usually appearing at the tops of the plants. To prevent this, you can spray the leaves with Oenosan every three weeks once the shoots emerge from the soil.
Sclerotinia stem rot
Excess nitrogen can make Jerusalem artichokes more prone to Sclerotinia stem rot, a disease that causes fungal growth on damaged plant parts, leading to hollow stems filled with mycelium that resembles rat droppings. If this occurs early, the foliage will die, and later infections can cause the tubers to rot.
How to use Jerusalem artichokes in the kitchen?
Jerusalem artichokes can be roasted, fried, stewed, or boiled. If you are cooking them for the first time, start with a small amount and ensure they are well-cooked, as undercooked tubers can cause digestive issues, including diarrhea for some people.
Are Jerusalem artichoke leaves edible? The young leaves tend to be bitter and are not typically consumed. In commercial production, the foliage is often used as animal feed after being cut down.
Some quick tips:
- Do not overcook the tubers—they're done when a fork can just about pierce them.
- Jerusalem artichokes will brown after peeling, so place them in water immediately after peeling to prevent discoloration.
For the best Jerusalem artichoke recipes, check out my blog “the best recipes with Jerusalem artichokes!”