Celeriac
Apium graveolens var. rapaceum
Apiaceae · carrot family
- Matures
- 100–180 days
- Harvest
- Once · Annual
- Sun
- 6–8+ hrs
- Spacing
- 6–12 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 |
Well-suitedMarginalNot suited
Sunlight
How well it does at each level of direct sun per day.
<2 hrsNot suited
2–4 hrsNot suited
4–6 hrsMarginal
6–8 hrsWell-suited
8+ hrsWell-suited
Well-suitedMarginalNot suited
Soil depth
Root room it needs — useful for sizing raised beds and containers.
6–10"Well-suited
10–15"Well-suited
15–18"Well-suited
18–24"Well-suited
Well-suitedMarginalNot suited
Spacing
Room each plant needs — along the row and between rows — for sizing beds.
- In-row
- 6–12 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
- Low mound
- Mature height
- 1.5–2 ft
Low and self-supporting — no staking needed.
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
- Transplant
- Start indoors
- 6–8 weeks ahead
Direct-sowNot suited
TransplantWell-suited
Started under cover, then set out as a seedling.
Well-suitedMarginalNot suited
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 seed
- Ideal soil temp
- 70–75°F
- Sow depth
- 0.25 in
- Time to emerge
- 14–21 days
Germinates between 40–85°F; happiest around 70–75°F.
30°F110°F
IdealWorkable
Pests & diseases
What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.
Same species as celery; shares its pests and diseases.
Pests1
Aphids
- What it is
- Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface.
- What you'll see
- Low to moderate numbers of leaf-feeding aphids aren't usually damaging in gardens or on trees. However, large populations can turn leaves yellow and stunt shoots; aphids can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus.
- What to do
- Before planting vegetables, check surrounding areas for sources of aphids and remove these sources. On the other hand, these aphid-infested weeds can sometimes provide an early source of aphid natural enemies.
Diseases2
Powdery Mildew
- What you'll see
- Older leaves and leaf petioles of plants with powdery mildew may be covered with a white powdery growth. Young leaves develop small circular white powdery spots that slowly enlarge to cover the leaflets.
- What to do
- In most cases, planting resistant varieties or avoiding the most susceptible varieties and following good cultural practices will adequately control powdery mildew. Provide enough water and avoid excess fertilizer.
Black Heart
- What you'll see
- Black discoloration of leaves in the center of the plant. Affected tissue eventually dies. Injury occurs gradually and is not visible until later in the season. This nutrient imbalance is a localize deficiency of calcium which is essential for cell development.
- What to do
- Control black heart applying calcium rich fertilizers to the soil. Use bone meal, blood meal, or calcium sprays. Avoiding water stress is a good way to minimize this problem.
Sources
Every figure above is backed by these.
- UC Master Gardeners, Sonoma Countybacks plantingWindow, sunlight, soilDepth, daysToMaturity, inRowSpacing · UC MG Sonoma Celeriac page. Window: 'Success depends on exposure to mild temperatures like those near the coast with a range from 50-75 degrees while it grows' (foggy SF's mild coast is ideal — a long spring-summer growing window) but 'Avoid planting in cool soil or plants will run to seed without forming a large root', so transplants go out after soil warms (Apr-Jun = yes, Mar = maybe). Foggy blocks hold 50-75 through summer so Jun stays yes and Jul = maybe; sunnier blocks heat past 75 in midsummer, so Jun drops to maybe and Jul to no. Light: 'Locate planting beds in full sun or very light shade' (6-8/8+ = yes, 4-6 = maybe). Soil: 'Celeriac is shallow rooted and requires even, regular watering' (shallow-rooted, all depth bands yes). Days: 'Plan on 100-150 days to maturity' (100 floor). Spacing: plants go in '10-12 in. apart' (the 12 ceiling of the 6-12 range).
- UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, lifecycle, harvestStyle, rowSpacing, startMethod · Vegetable Planting Summary, 'Celeriac' row: 150-180 days to maturity (the 180 ceiling; SF's cool short days push it to the long end), 6-8 in in-row spacing (the 6 floor of the 6-12 range). Season C* (hardy cool). Notes 'Needs high fertility and water. Harvest 3 in wide roots in fall and winter.' Habit and harvest: annual, once — consistent with this source's planting-summary row. Between-row spacing 12 in (Celeriac row). Start method: Vegetable Planting Summary, Celeriac row: method T. The table's legend defines T as 'usually transplanted (start seed indoors 6-8 wks ahead)' — the lead time here is that legend figure, which is stated for the table's T crops generally rather than for celeriac specifically.
- Cornell University Home Gardeningbacks germination · Cornell Home Gardening celeriac (Apium graveolens, same species as celery): optimum germination 70–75°F; emergence 14–21 days; min 40°F floor per GN 154 celery.
- USDA GRIN Taxonomybacks botany
- Penn State Extensionbacks plantingDepth · Penn State MG Vegetable Seed Planting Guide, Celeriac row: sow seeds 1/4 in deep.
- NC State Extension — Plant Toolboxbacks growthHabit · Apium graveolens (celeriac is var. rapaceum of this species): 'Height: 1 ft. 6 in. - 3 ft. 0 in.', plant 'grows up to 1.5 to 3 feet tall' as an erect clump of celery-like foliage. Stored 18-24 in for the harvest-year leafy clump (below the ~3 ft second-year bolting height); self-supporting basal clump, no stake (low-mound).