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Entire healthy mature cauliflower plant in a real garden bed, showing growth habit and scale.Primary identification image. 45–60 cm tall, 45–60 cm wide at maturity.

Cauliflower

Brassica oleracea var. botrytis L.

Family
Brassicaceae
Season
Cool-season annual or biennial
Best grown in
Portland, Oregon

The fussiest brassica: any check from cold, drought or transplant shock produces tiny "button" heads.

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Life cycle & growth stages

  1. 1. SeedSow indoors 6–8 weeks before last frost.
  2. 2. SeedlingGrow on without checks.
  3. 3. TransplantSet out at 4–6 weeks; water in.
  4. 4. Mid-growthLarge leaves; feed and water steadily.
  5. 5. Curd formingBlanch white curds by folding leaves over.
  6. 6. Harvest readyCurd tight, 15–20 cm.
  7. 7. HarvestCut with a few wrapper leaves.

Growth stages are ordered chronologically; timing varies with cultivar, temperature, light and care.

Planting calendar for Portland, Oregon

Start indoors 6–8 weeks before last frost; transplant 2 weeks before to 1 weeks after last frost; 55–80 days to maturity from transplant. Windows are derived from the region's average frost dates (last Apr 5, first Nov 5) and are estimates until you confirm your own dates in the calendar.

CauliflowerBrassica oleracea var. botrytis
PlantStart indoorsDirect sowAutumn sowTransplantTendHarvest
CauliflowerFeb 8–Feb 22 (estimate)—Jul 30–Aug 13 (estimate)Mar 22–Apr 12 (estimate)Apr 12–May 16 (estimate)May 16–Jul 15 (estimate)
  • Start seeds indoors: Feb 8 – Feb 22
  • Transplant outdoors: Mar 22 – Apr 12
  • Tend and monitor: Apr 12 – May 16
  • Harvest: May 16 – Jul 15
  • Autumn sowing: Jul 30 – Aug 13

Spacing & support

In-row 45–60 cm; rows 60–90 cm. Planner footprint: 2 cells of 30 cm.

Side-profile diagram of mature cauliflower: canopy 45–60 cm tall, 45–60 cm wide, medium root zone, support and harvest-access envelope.

Soil & water

Soil
Very fertile, moisture-retentive loam
pH
6.5–7.5
Fertility
high
Water
Never let plants dry out; stress causes buttoning.
Frost
half hardy; tolerates frost

Support & training

No support structure needed.

Cauliflower mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.

Harvest signs

  • Curd 15–20 cm across, tight and smooth
  • Cut before florets begin to separate
Cauliflower at harvest readiness, showing the visual cues: curd 15–20 cm across, tight and smooth; cut before florets begin to separate.

Common problems

Pests: cabbage white caterpillars, cabbage root fly, cabbage aphid

Diseases: clubroot, black rot

Appearance alone is not a diagnosis; confirm with a regional extension guide.

Side-by-side: healthy cauliflower leaf or fruit and an example of clubroot.

Container growing

Possible in 25 L containers but unforgiving of drought.

Companion overview

1 reviewed relationship record (evidence: low).

Supported or conditional

None reviewed

Avoid or separate

None with evidence

1 popular pairing reviewed with no verified relationship.

Full companion profile

Crop rotation

Avoid planting cauliflower or other cabbage family crops in the same spot for 3 years. Rotation is about previous seasons, not about live neighbours.

Year 1Year 2Year 3BrassicaceaeOther familyOther familyback after 3+ years

Shared risks in Brassicaceae: clubroot, cabbage root fly, cabbage white caterpillars.

Crop rotation hub

Sources, reviewer & update

Sources

Reviewer: Garden Planner editorial team (pending independent horticultural review)

Last reviewed: August 15, 2026 · version 1

Found an error or have feedback? Let us know.

Growing cauliflower

Cauliflower needs unbroken, even growth. Transplant at 4–6 weeks old without letting seedlings become root-bound or cold-stressed, keep water constant and feed well. Spring crops should mature before heat; autumn crops, transplanted in midsummer, are usually more reliable.

Cauliflower seed beside a ruler or coin for scale.
Cauliflower seedling at cotyledon and first-true-leaf stage, in soil, distinguishable from common weeds.
Cauliflower at transplant-ready stage with root ball visible beside the cell or pot.

Fold or tie outer leaves over developing white curds to keep them pale. Purple, orange and green cultivars do not need blanching.

Two or more mature cauliflower plants with a tape measure showing in-row spacing (45–60 cm).
Cauliflower flower detail or bolting stage.
Immature flower head of cauliflower developing on the plant.

All cabbage pests and diseases apply; mesh cover from transplanting and a three-year rotation are the standard defences.

Edible parts and safety

Edible: flower head (curd).

Hands or tool harvesting cauliflower correctly (cut, pull, twist or pick) without damaging the plant.

Pests and diseases

Common pests: cabbage white caterpillars, cabbage root fly, cabbage aphid. Common diseases: clubroot, black rot. These vary by region; a photograph is an example, not a diagnosis. See the pest and disease guides and your local extension service.

cabbage white caterpillars on cauliflower, with a wider damage-context view.

Timeline

Season timeline for cauliflower: sowing, transplanting, flowering, harvest and bed occupancy aligned to frost dates.Text alternative: Start seeds indoors Feb 8–Feb 22; Transplant outdoors Mar 22–Apr 12; Tend and monitor Apr 12–May 16; Harvest May 16–Jul 15; Autumn sowing Jul 30–Aug 13.

Related plants

See also: Brassicaceae family page · crop rotation · regional calendar · guides

Our Methodology & Sources

We synthesize peer-reviewed research, university extension publications, and trusted horticulture resources. Our evidence levels help you understand how strong the science is behind the guidance.

Evidence tiers

Supported evidenceConsistent results from multiple robust studies
Traditional claimHistorical use reported, limited scientific support
Context dependentMixed or variable results across conditions
No verified relationshipNo reliable evidence identified

Primary source types

  • Peer-reviewed journal articles
  • University extension publications
  • Government & research institute reports
  • Systematic reviews & meta-analyses

Last updated

August 24, 2026

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