Sunchoke
Helianthus tuberosus
Asteraceae · sunflower family
- Matures
- 125 days
- Harvest
- Once · Perennial
- Sun
- 4–8+ hrs
- Spacing
- 12 in
Planting window
When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.
| Jan | Feb | Mar | Apr | May | Jun | |
|---|---|---|---|---|---|---|
| Foggy | ◐ | ● | ● | ● | ◐ | |
| Sunny | ◐ | ● | ● | ◐ | ◐ |
| Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|
| Foggy | ||||||
| Sunny |
Sunlight
How well it does at each level of direct sun per day.
Soil depth
Root room it needs — useful for sizing raised beds and containers.
Spacing
Room each plant needs — along the row and between rows — for sizing beds.
- In-row
- 12 in
- Between rows
- 12 in
Growth habit
The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.
- Habit
- Upright
- Mature height
- 10–12 ft
Stands on its own; the tallest types appreciate a stake in wind.
How to start it
Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.
- Usually
- Direct-sow
Sown straight into the bed it will grow in.
Getting started
How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.
- Started from
- From tubers
- Ideal soil temp
- 45–75°F
- Set depth
- 2 in
Sprouts between 45–90°F; happiest around 45–75°F.
Pests & diseases
What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.
Our sources document no specific pests or diseases for this crop; it's generally grown without major pest trouble in home gardens.
Sources
Every figure above is backed by these.
- Golden Gate Gardening (Pam Peirce)backs plantingWindow, lifecycle, harvestStyle · Foggier/Sunnier planting-times charts, 'Sunchoke (Tubers)' row: foggier Jan light, Feb-Apr heavy, May light; sunnier Jan light, Feb-Mar heavy, Apr-May light. Tubers go in over late winter and early spring in both microclimates. Habit and harvest: perennial, once — from this source's entry for this crop.
- UC Master Gardeners, Marin Countybacks sunlight, daysToMaturity, inRowSpacing, rowSpacing, plantingDepth, growthHabit · Sunchoke grow sheet — the only UC source in this knowledge base that covers the crop; Sonoma's planting summary omits it. Sunlight: 'Sunchokes prefer a sunny location. They will reach for the sun if planted in partial shade' and 'Though it will produce well in partial shade, it's more likely to flower with more sun' — a sun-preferring plant that still crops in part shade, so 4-6 hrs is workable and 2-4 marginal. Days: 'Sunchokes need at least 125 days to produce mature vegetables' — a floor, not a range, so min equals max. Spacing: 'In the ground: Plant two inches deep and one foot apart' -> 12 in (the 2 in is tuber planting depth, not soil depth). Between-row spacing is taken equal to the in-row figure: this crop is spaced about equally in all directions and the source gives a single spacing, not a distinct row width. Planting depth 2 in (tuber): 'In the ground: Plant two inches deep and one foot apart.' GROWTH HABIT: 'Plants grow 10 to 12 feet tall' and sunchoke is 'a relative of the sunflower' -> classified upright (a tall, self-supporting Helianthus). Stored height 120-144 in (10-12 ft) is the plant's own vertical extent.
- UC Master Gardeners, Santa Clara County (Containers)backs soilDepth · Soil-depth-by-crop has no sunchoke row; assigned deep-rooted (18-24 in) by parity with potatoes, the other tuber crop it lists, which it files as deep-rooted. Marin's grow sheet gives no rooting depth — its 'two inches deep' is where the tuber is set, not how deep the roots run — so parity is the only citable basis.
- Ohio State University Extension (Ohioline)backs germination · Ohio State Ohioline (ANR-0167): plant tubers when soil reaches 6–7°C (≈43–45°F) — the establishment floor. No crop-specific upper soil-temp is published; optimal/max reflect its hardy warm-season habit (planted spring, harvested after fall frost).
- USDA GRIN Taxonomybacks botany
- UC Master Gardeners, Marin Countybacks startMethod · Start method: UC Marin MG sunchoke: tubers are planted directly into the bed at depth, the same way seed potatoes are — no seedling stage exists to raise under cover.