Jerusalem artichoke
Helianthus tuberosus
A perennial sunflower producing knobbly tubers, almost impossible to fail with and almost impossible to get rid of: any fragment left in the ground regrows. Plant it where you are content for it to stay, and treat the two-metre screen of growth as the main crop rather than an inconvenience.
- Position
- Full sun or Partial shade
- Water
- low demand
- Drainage
- Free-draining, Moisture-retentive
- Grows to
- 180–250 cm × 60–90 cm
- Hardiness
- H6
- Harvest
- November to February
- Difficulty
- Straightforward
August
Nothing to do
No sowing, planting, harvesting or pruning window falls in August.
Jerusalem artichoke’s year
Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.
| Activity | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plant | February. | March. | ||||||||||
| Harvest | January. | February. | November. | December. |
Timing that travels
The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.
Conditions it needs
- Light
- Full sun, Partial shade
- Frost
- Very hardy
- Hardiness rating
- H6 (RHS)
- Grows best at
- 15–25 °C
- Soil
- Sandy, Loam, Clay
- Soil pH
- 5.5–7.5
- Drainage
- Free-draining, Moisture-retentive
- Water needs
- low
- Drought
- good tolerance
- Waterlogging
- moderate tolerance
- Heat
- good tolerance
- Wind and exposure
- poor tolerance
Where these figures come from
- LightSourced guidancemoderate confidence
- Royal Horticultural Society: Jerusalem artichoke — position
Checked 2026-08-13
- FrostSourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke — hardiness
Checked 2026-08-13
- Hardiness ratingSourced guidancemoderate confidence
- Royal Horticultural Society: RHS hardiness ratings
Checked 2026-08-13
- Grows best atSourced guidancemoderate confidence
- Royal Horticultural Society: Jerusalem artichoke — temperature
Checked 2026-08-13
- SoilSourced guidancemoderate confidence
- Royal Horticultural Society: Jerusalem artichoke — soil
Checked 2026-08-13
- Soil pHSourced guidancemoderate confidence
- Plant Finder — Missouri Botanical Garden: Helianthus tuberosus — culture
Checked 2026-08-13
- DrainageSourced guidancemoderate confidence
- Royal Horticultural Society: Jerusalem artichoke — soil
Checked 2026-08-13
- Water needsHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- DroughtHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- WaterloggingHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- HeatHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Wind and exposureHorticultural consensusmoderate confidence
Two metres of top growth blows over; the tubers are unaffected.
No external citation — see the evidence type above.
Checked 2026-08-13
On your soil
Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.
| Soil | Verdict | Why |
|---|---|---|
| Heavy clay | Works, with one condition | Jerusalem artichoke will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse. |
| Sandy | Prefers this soil | Sandy suits Jerusalem artichoke as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Sandy soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Chalky and alkaline | Grows well here | Jerusalem artichoke grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Loam | Prefers this soil | Loam suits Jerusalem artichoke as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering. |
| Silty | Prefers this soil | Silty suits Jerusalem artichoke as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering. |
| Peaty and acid | Works, with one condition | Jerusalem artichoke will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse. |
| Shallow over rock | Prefers this soil | Shallow over rock suits Jerusalem artichoke as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Made ground and urban soil | Works, with one condition | Jerusalem artichoke will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse. |
Not sure which you have? Four hand tests will settle it.
Space and spacing
- Mature height
- 180–250 cm
- Mature spread
- 60–90 cm
- Rooting depth
- 45 cm
- Spacing
- 30–45 cm apart
Where these figures come from
- Mature heightHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Mature spreadHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Rooting depthHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- SpacingSourced guidancemoderate confidence
- Royal Horticultural Society: Jerusalem artichoke — spacing
Checked 2026-08-13
In a container
- Minimum volume
- 30 litres or more
- Minimum depth
- 40 cm
Where the container figures come from
- Minimum volumeHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
- Minimum depthHorticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13
A large container is genuinely the sensible way to grow this, because it is the only reliable way to contain it.
Where and how you can grow it
Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.
| Method | Suitability | What it needs |
|---|---|---|
| Open ground | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Traditional dug bed | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Raised bed | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Container | Well suitedsourceSourced guidancemoderate confidence
Checked 2026-08-13 | 30 litres; Chosen for containment rather than for space |
| Hydroponics | Not suitablesourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Greenhouse | Not suitablesourceSourced guidancemoderate confidence
Checked 2026-08-13 | |
| Polytunnel | Not suitablesourceSourced guidancemoderate confidence
Checked 2026-08-13 |
Growing it
- SupportCut the stems back to about 1.5 m in midsummer on an exposed site. Two and a half metres of top growth acts as a sail and the whole clump goes over in the first autumn gale.
- HarvestingLift the whole clump rather than picking through it, and sift the soil. Any fragment left behind regrows, which is how a bed becomes permanent whether or not that was the intention.
Where this guidance comes from
- SupportSourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke — care
Checked 2026-08-13
- HarvestingSourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke — care
Checked 2026-08-13
Is it worth putting under cover?
Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.
| Structure | What protection is worth | What decides it |
|---|---|---|
| Greenhouse | Worse under coversourceGrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file.
Checked 2026-08-13 | Height. The plant reaches two to three metres and would fill the house to the ridge for a tuber that grows in any neglected corner outdoors. |
| Polytunnel | Worse under coversourceGrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file.
Checked 2026-08-13 | Height, and a spreading tuber that is very hard to remove from a permanent bed once it is in. |
Harvesting
- When it is readyReady once the stems have blackened and died down after the first frosts, usually from November. The tubers keep far better in the ground than out of it, so dig as needed right through to March. Flavour improves with cold.
- How to pick itCut the stems down to about 30 cm first so you can see where the row is, then fork the tubers out carefully. Take every fragment you can find: any tuber left behind grows again next year, which is how a bed of Jerusalem artichokes becomes permanent whether or not that was the plan.
Where the harvest guidance comes from
- When it is readySourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke — harvesting
Checked 2026-08-13
- How to pick itSourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke — harvesting
Checked 2026-08-13
What goes wrong
| Problem | How often | Notes |
|---|---|---|
| Slugs and snails | uncommonsourceHorticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13 |
Safety and edibility
- PreparationThe tubers are high in inulin, a carbohydrate many people cannot digest. It ferments in the gut and causes considerable flatulence and abdominal discomfort — which is where the vegetable's other common name comes from.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Jerusalem artichoke
Checked 2026-08-13
Introduce it in small quantities and find your own tolerance before serving a large dish to guests. Tolerance varies widely between people and does build with regular small amounts.
Sources for this page
Agriculture and Horticulture Development Board · GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society
Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.