All plants

Winter Radish

Raphanus sativus

Brassicaceae · cabbage family

Matures
50–70 days
Harvest
Once · Annual
Sun
4–8+ hrs
Spacing
4–8 in
Botanical engraving of Winter Radish

Planting window

When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.

JanFebMarAprMayJun
Foggy●●●◐◐
Sunny●●◐◐◐
JulAugSepOctNovDec
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
4–8 in
Between rows
8–12 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
1–2 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
Direct-sowWell-suited
TransplantNot 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
65–85°F
Sow depth
0.5 in
Time to emerge
4–6 days

Germinates between 40–95°F; happiest around 65–85°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

Cucumber Beetles
What it is
Adult beetles are shiny with black heads, long antennae, and about 1/4 inch long. Adults may be striped or spotted, depending upon species.
What you'll see
Adults feed on the leaves of many vegetables as well as on soft fruit. Shoots and blossoms may also be consumed.
What to do
Management of cucumber beetles is difficult. The best strategy for most vegetable gardens may be to place protective cloth over emerging plants and remove it when plants are old enough to tolerate damage.
Source
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.
Source
Harlequin Bug
What it is
Harlequin bugs can be confused with Bagrada bugs, an invasive species, but are much larger and lack the white markings characteristic of Bagrada bugs. Harlequin bugs may also be confused with stink bugs.
What you'll see
Harlequin bugs suck fluids from plant tissue. They leave yellow or white blotches on areas of leaves where they have been feeding; heavy infestations can cause plants to wilt, turn brown, and die.
What to do
Handpick bugs or their eggs. Destroy old cole crop plants and mustards because they provide breeding areas.
Source

Sources

Every figure above is backed by these.

  • Golden Gate Gardening (Pam Peirce)backs plantingWindow, lifecycle, harvestStyle · Foggier/Sunnier planting-times charts, '*Radish (winter)' row — the only source that separates winter radish from the small spring types (our `radish` crop cites the 'Radish (small)' row instead). Foggier: Jan-Mar heavy, Apr-May light, Jul light, Aug-Sep heavy. Sunnier: Jan-Feb heavy, Mar-May light, Jul light, Aug-Sep heavy. The leading '*' is Peirce's mark that varieties differ widely in timing, which her legend spells out for this very crop: 'most winter radishes should be planted from mid-summer into fall, but some varieties can be planted in the spring' — the Jul-Sep block and the spring light-shading respectively. Habit and harvest: annual, once — from this source's entry for this crop.
  • UC Master Gardeners, Marin Countybacks sunlight, inRowSpacing, plantingDepth · Radish grow sheet, which names winter radish and daikon explicitly. Sunlight: 'In sunny, hot microclimates, plant radishes where they will receive some shade. In foggy areas, plant where they will receive full sun all day.' — so full sun is right for SF, with part shade tolerated (2-4 hrs marginal). Spacing: 'Plant four to eight inches apart', and 'Larger winter varieties need more space than spring varieties so thin to the farther spacing.' Planting depth 1/2 in: 'Direct seed thinly and half inch deep.'
  • UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, soilDepth, rowSpacing, startMethod · Vegetable Planting Summary, 'Radishes, Daikon and winter' row (distinct from its plain 'Radishes' row): 50-70 days, 4-8 in in-row spacing. Its note 'Grow in deep, loose soil' is the qualitative basis for treating this crop as deeper-rooted than the small radishes, which uc-mg-santa-clara-containers files as shallow-rooted at 6-9 in. Sonoma's Aug-Sept inland timing is not used for SF. Between-row spacing 8-12 in (Radishes, Daikon and winter row). Start method: Vegetable Planting Summary, Radishes, Daikon and winter row: method D (usually direct-sown).
  • University of Minnesota Extensionbacks soilDepth · Growing radishes: 'Loosen soil before planting at least six inches deep, a foot or more for long types.' The long (winter/daikon) types therefore need 12 in or more, which is what puts this crop in the moderate-to-deep bands rather than the shallow 6-10 in one. Minnesota is not SF, so this is used for rooting depth only — a location-independent agronomy fact — and never for timing.
  • UC Master Gardeners, Sacramento County (Germination)backs germination · Winter/daikon radish is Raphanus sativus, the same species as radish; GN 154 Radishes row: 40/65–85/95°F, days 4–6 from Table 2 optimum band.
  • USDA GRIN Taxonomybacks botany · GRIN treats var. longipinnatus (daikon) as a synonym, so winter and spring radish share an accepted name and differ only by cultivar group.
  • University of Arkansas Cooperative Extensionbacks growthHabit · Plant of the Week, Daikon Radish: the plant is 'topped with a foot-long crown of scalloped leaves' (~12 in of foliage) above the taproot -- a low leafy rosette, no support (low-mound).
  • NC State Extension — Plant Toolboxbacks growthHabit · Raphanus raphanistrum subsp. sativus (common names include Daikon): 'Height: 0 ft. 6 in. - 3 ft. 0 in.'; large winter/daikon types reach the upper end of that range. Stored 12-24 in foliage-top range (foot-long crown per Arkansas up to the larger daikon leaf mass); low-mound rosette.
  • UC Master Gardeners, San Mateo–SF Countiesbacks startMethod · Start method: Foggy & Sunny calendars, Radish row: (S) sow seed only.
  • UC Master Gardeners, Santa Clara Countybacks startMethod · Start method: Planting chart: Daikon carries a Direct seed row only, From seed to transplant Not applicable.