Rutabaga
Brassica napus subsp. rapifera
Brassicaceae · cabbage family
- Matures
- 90–120 days
- Harvest
- Once · Annual
- Sun
- 4–8+ hrs
- Spacing
- 6–10 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 hrsMarginal
4–6 hrsWell-suited
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"Not suited
10–15"Marginal
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
- 6–10 in
- Between rows
- 18–24 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
- 1–2 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
- Direct-sow
- Start indoors
- 4 weeks ahead
Direct-sowWell-suited
TransplantWell-suited
Sown straight into the bed it will grow in.
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
- 60°F
- Sow depth
- 0.25 in
- Time to emerge
- 4–7 days
Germinates between 40–85°F; happiest around 60°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.
Pests3
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.
Cabbage Worms
- What you'll see
- Worms are light to dark green. Adult moths are gray, brown or white. Worms chew holes in leaves and hide in and under leaves.
- What to do
- Control worms with chemical or biological measures.
Flea Beetles
- What it is
- Their small size, enlarged back legs, characteristic shot-hole damage, and habit of jumping when disturbed make flea beetles easy to identify. There are numerous flea beetle species.
- What you'll see
- Adults feed mostly on leaves, leaving tiny pits or small holes at their feeding sites. Flea beetles feeding together can cover leaves with bleached, pitted areas or ragged holes.
- What to do
- Remove debris in the fall to remove any overwintering beetles. Reflective mulches applied very soon after planting and before plants become infected can be helpful.
Diseases1
Alternaria Leaf Spot
- What you'll see
- Damping off of seedlings. Leaf spots on leaves or heads are a more common symptom. Spots form concentric circles which have a black sooty color.
- What to do
- Apply appropriate chemicals. Avoid overhead irrigation. Practice good sanitation. Rotate crops.
Sources
Every figure above is backed by these.
- UC Master Gardeners, Santa Clara Countybacks plantingWindow, daysToMaturity, inRowSpacing · UC MG Santa Clara Rutabagas page: 'Direct seed in August and September; thin to 6 to 10 inches apart' and 'Transplant 6 to 10 inches apart in September and October' (Bay Area window Aug-Oct = yes/maybe; spacing 6-10 in). 'Harvest when roots reach desired size, typically 3 to 5 inches, in 3 to 4 months' (days-to-maturity ceiling ~120). 'They develop their best flavor in cool weather' and 'Flavor is best if there have been some light frosts' — a fall/winter-maturing crop, so summer and midwinter sowings are marginal.
- UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, lifecycle, harvestStyle, rowSpacing, startMethod · Vegetable Planting Summary, 'Rutabagas' row: 90 days to maturity (the floor; Santa Clara's 3-4 months gives the 120 ceiling), 6 in in-row spacing (floor of the 6-10 range). Season C (cool). Notes 'Direct seed. Best flavor in cool weather. Harvest at 2-3 in diameter.' Sonoma's Aug inland date is a touch warm for foggy SF; the SF window is anchored on Santa Clara's Aug-Oct and nudged earlier (Jul = maybe in cool foggy blocks). Habit and harvest: annual, once — consistent with this source's planting-summary row. Between-row spacing 18-24 in (Rutabagas row). Start method: Vegetable Planting Summary, Rutabagas row: method D (usually direct-sown).
- Utah State University Extensionbacks sunlight, inRowSpacing, plantingDepth · USU 'How to Grow Rutabagas and Turnips in Your Garden' (agronomy only; Utah timing not used): 'Rutabagas and turnips are cool season vegetables that prefer sunny locations' (full sun 6-8/8+ hrs = yes; part shade 4-6 = yes, 2-4 = maybe). 'After emergence, thin rutabagas, spacing them 4-6 inches between plants' corroborates the lower end of the 6-10 in-row range. Planting depth 1/4 in: 'Seeds should be planted 1/4 inch deep.'
- UC Master Gardeners, Santa Clara County (Containers)backs soilDepth · No rutabaga row; assigned moderate-to-deep (12-18 in min: 6-10 = no, 10-15 = maybe, 15-18/18-24 = yes) by parity with the taprooted root crops. Rutabaga forms a large 3-5 in swollen root on a deep taproot, so it wants a loose foot-plus of soil — deeper than the shallow greens, on par with beet/turnip.
- Cornell University Home Gardeningbacks germination · Cornell rutabaga: germination 45–85°F, 60°F optimum, as low as 40°F; emergence 4–7 days
- USDA GRIN Taxonomybacks botany
- NC State Extension — Plant Toolboxbacks growthHabit · Brassica napus (Napobrassica Group), rutabaga: 'Height: 1 ft. 0 in. - 2 ft. 0 in.' A 12-24 in leafy top above the swollen root, no support (low-mound).
- UC Master Gardeners, Santa Clara Countybacks startMethod · Start method: Planting chart: Rutabagas carry both rows; From seed to transplant 4 weeks.