Vegetable Guide
Cauliflower
Brassica oleracea var. botrytis
Cauliflower is a cool-season cole crop in the Brassicaceae family grown for its compact immature flower head, or curd. It is more sensitive to temperature stress than most other cole crops and performs best with steady growth, fertile well-drained soil, consistent moisture, and mild temperatures. Zone 9 is well suited to fall, winter, and early-spring cauliflower production. UF/IFAS lists cauliflower planting from August through February in North Florida, September through February in Central Florida, and September through January in South Florida. UC ANR notes that cauliflower grows best under cool conditions and is especially sensitive to prolonged cold and excessive heat, both of which can disrupt head formation.
Sun
Full sun, preferably 6+ hours daily; at least 4–6 hours
Days to Maturity
80 days
Plant Type
Vegetable / Cool-Season Cole Crop
Planting Windows for Zone 9
| Stage | Spring | Fall |
|---|---|---|
| Start Indoors | Dec 15 – Jan 31 | Jul 1 – Aug 31 |
| Direct Sow | Jan 1 – Feb 15 | Aug 1 – Sep 30 |
| Transplant | Jan 15 – Mar 1 | Aug 15 – Oct 31 |
| Harvest | Mar 15 – May 31 | Oct 15 – Mar 31 |
Recommended Cauliflower Varieties
Snow Crown — Widely recommended by UF/IFAS and UC ANR; early, dependable white cauliflower with good adaptability.
Snowball Strains — Traditional white cauliflower types recommended by UF/IFAS for Florida gardens.
Snow King — White cauliflower recommended by UC ANR for home gardens.
Majestic — Hybrid cauliflower recommended by UF/IFAS for Florida production.
Whistler — Hybrid white cauliflower recommended by UF/IFAS.
White Passion — Hybrid white cauliflower recommended by UF/IFAS.
Graffiti — Purple cauliflower listed by UC ANR; provides colorful heads while using the same basic culture as white types.
Cheddar — Orange cauliflower listed by UC ANR.
Romanesco — Green spiral-headed cauliflower type listed by UC ANR.
Fertilizer Schedule
Pre-Plant — 1–3 Weeks Before Planting
Incorporate finished compost or other organic matter and apply fertilizer according to a soil test. Where phosphorus is needed, incorporate it before planting. A target pH of about 6.5 is appropriate for cauliflower, with phosphorus and potassium based on soil-test results.
Incorporate finished compost or other organic matter and apply fertilizer according to a soil test. Where phosphorus is needed, incorporate it before planting. A target pH of about 6.5 is appropriate for cauliflower, with phosphorus and potassium based on soil-test results.
At Planting / Transplanting — Day 0
Set sturdy transplants with 4–6 true leaves, water thoroughly, and use a starter or balanced fertilizer only where soil fertility indicates a need. Keep concentrated fertilizer away from stems and roots.
Set sturdy transplants with 4–6 true leaves, water thoroughly, and use a starter or balanced fertilizer only where soil fertility indicates a need. Keep concentrated fertilizer away from stems and roots.
Early Growth — Plants About 3–4 Inches Tall or Once Transplants Are Established
Side-dress with a light nitrogen application and water it in.
Side-dress with a light nitrogen application and water it in.
Active Vegetative Growth — Every 3–4 Weeks If Needed
Consider light, frequent nitrogen applications during active growth, especially in sandy soil or after nutrient-leaching rainfall. Avoid overfertilization and keep fertilizer off plant stems.
Consider light, frequent nitrogen applications during active growth, especially in sandy soil or after nutrient-leaching rainfall. Avoid overfertilization and keep fertilizer off plant stems.
Head Development — As Curds Begin Forming
Maintain steady moisture. Avoid late heavy nitrogen applications once heading begins because excessive nitrogen at this stage can contribute to leafy or loose curds.
Maintain steady moisture. Avoid late heavy nitrogen applications once heading begins because excessive nitrogen at this stage can contribute to leafy or loose curds.
Planting Details
Seed Depth
0.5 inch; 0.25–0.5 inch range
0.5 inch; 0.25–0.5 inch range
Plant Spacing
18–24 inches for home gardens
18–24 inches for home gardens
Row Spacing
24–36 inches
24–36 inches
Germination Time
5–10 days under good growing conditions
5–10 days under good growing conditions
Germination Temperature
65–85°F optimum range; about 70–75°F is an excellent target
65–85°F optimum range; about 70–75°F is an excellent target
Minimum Soil Temperature
40°F minimum for seed germination
40°F minimum for seed germination
Optimal Soil Temperature
65–85°F for seed germination; cool-season establishment is best under mild soil and air temperatures
65–85°F for seed germination; cool-season establishment is best under mild soil and air temperatures
Growing Requirements
Sun
Full sun, preferably 6+ hours daily; at least 4–6 hours.
Full sun, preferably 6+ hours daily; at least 4–6 hours.
Water
Keep soil consistently and evenly moist from transplanting through head development. Water deeply to encourage a strong root system, avoid drought stress, and minimize prolonged leaf wetness when possible.
Keep soil consistently and evenly moist from transplanting through head development. Water deeply to encourage a strong root system, avoid drought stress, and minimize prolonged leaf wetness when possible.
Soil
Fertile, well-drained loam or sandy loam rich in organic matter; avoid compacted soil, shallow hardpans, and waterlogged conditions.
Fertile, well-drained loam or sandy loam rich in organic matter; avoid compacted soil, shallow hardpans, and waterlogged conditions.
Soil pH
6.0–6.5; about 6.5 is an excellent target.
6.0–6.5; about 6.5 is an excellent target.
Fertilizer
Moderate-to-heavy feeder. Base phosphorus and potassium on soil-test results and provide steady nitrogen for vegetative growth without excessive applications.
Moderate-to-heavy feeder. Base phosphorus and potassium on soil-test results and provide steady nitrogen for vegetative growth without excessive applications.
Fertilizer Schedule
Preplant compost and soil-test fertilizer → transplant or direct sow into prepared soil → light nitrogen side-dressing when plants are about 3–4 inches tall or established → repeat light nitrogen every 3–4 weeks if needed during active growth → reduce unnecessary late feeding as heads approach harvest.
Preplant compost and soil-test fertilizer → transplant or direct sow into prepared soil → light nitrogen side-dressing when plants are about 3–4 inches tall or established → repeat light nitrogen every 3–4 weeks if needed during active growth → reduce unnecessary late feeding as heads approach harvest.
Top 5 Common Cauliflower Pests
Imported Cabbageworm
Fall–Spring; active during mild weather
Velvety green caterpillars chew large irregular holes in leaves and may contaminate plants with frass. Heavy feeding reduces leaf area and can weaken developing plants.
Fall–Spring; active during mild weather
Velvety green caterpillars chew large irregular holes in leaves and may contaminate plants with frass. Heavy feeding reduces leaf area and can weaken developing plants.
Cabbage Looper
Fall–Spring; often active during mild weather
Green looping caterpillars chew ragged holes in leaves. Heavy populations can remove substantial foliage and reduce plant vigor and head development.
Fall–Spring; often active during mild weather
Green looping caterpillars chew ragged holes in leaves. Heavy populations can remove substantial foliage and reduce plant vigor and head development.
Diamondback Moth
Fall–Spring; often strongest in mild dry periods
Small green larvae feed mainly on leaf undersides, first creating window-like patches and later small holes. Heavy infestations can seriously damage young plants.
Fall–Spring; often strongest in mild dry periods
Small green larvae feed mainly on leaf undersides, first creating window-like patches and later small holes. Heavy infestations can seriously damage young plants.
Aphids
Fall–Spring; populations often increase during cool-to-mild weather
Aphid colonies cluster on leaves and within developing heads, causing curling, yellowing, reduced vigor, sticky honeydew, and contamination of harvested heads.
Fall–Spring; populations often increase during cool-to-mild weather
Aphid colonies cluster on leaves and within developing heads, causing curling, yellowing, reduced vigor, sticky honeydew, and contamination of harvested heads.
Cabbage Maggot
Cool, wet periods; Fall–Spring
White larvae feed on roots and underground stems, causing stunting, yellowing, wilting, poor growth, and sometimes plant death. Root wounds can also allow secondary decay.
Cool, wet periods; Fall–Spring
White larvae feed on roots and underground stems, causing stunting, yellowing, wilting, poor growth, and sometimes plant death. Root wounds can also allow secondary decay.
Top 5 Common Cauliflower Diseases
Downy Mildew
Cool, moist or humid weather; Fall–Spring
Irregular yellow patches develop on leaves and later turn tan to brown. White fluffy growth may appear on leaf undersides. Systemic infection can produce internal black streaks in cauliflower stems and floret branches.
Cool, moist or humid weather; Fall–Spring
Irregular yellow patches develop on leaves and later turn tan to brown. White fluffy growth may appear on leaf undersides. Systemic infection can produce internal black streaks in cauliflower stems and floret branches.
Black Rot
Warm, wet or humid conditions
Yellow V-shaped lesions develop from leaf margins and veins may darken as bacteria move through vascular tissue. Severe infection causes stunting, leaf loss, poor head development, and postharvest deterioration.
Warm, wet or humid conditions
Yellow V-shaped lesions develop from leaf margins and veins may darken as bacteria move through vascular tissue. Severe infection causes stunting, leaf loss, poor head development, and postharvest deterioration.
Clubroot
Cool-to-moderate moist soil; especially acidic infested soil
Roots become enlarged, distorted, and club-shaped. Aboveground plants become stunted, yellow, and may wilt during warm parts of the day even when soil moisture is adequate.
Cool-to-moderate moist soil; especially acidic infested soil
Roots become enlarged, distorted, and club-shaped. Aboveground plants become stunted, yellow, and may wilt during warm parts of the day even when soil moisture is adequate.
Bacterial Leaf Spot
Cool-to-mild wet conditions; favored by splashing rain or overhead irrigation
Small dark specks enlarge into numerous water-soaked spots that later become tan and may have purple margins. Severe spotting reduces healthy leaf area and can weaken plants.
Cool-to-mild wet conditions; favored by splashing rain or overhead irrigation
Small dark specks enlarge into numerous water-soaked spots that later become tan and may have purple margins. Severe spotting reduces healthy leaf area and can weaken plants.
Bacterial Soft Rot
Warm, wet conditions; often after injury or prolonged moisture
Water-soaked tissue becomes soft, mushy, and rapidly decayed. Infection can damage stems and heads and may produce foul-smelling breakdown under warm, wet conditions.
Warm, wet conditions; often after injury or prolonged moisture
Water-soaked tissue becomes soft, mushy, and rapidly decayed. Infection can damage stems and heads and may produce foul-smelling breakdown under warm, wet conditions.
Zone 9 Weather Patterns
Cold Exposure After the Juvenile Stage
Several days of cold temperatures can trigger premature small heads, known as buttoning.
Several days of cold temperatures can trigger premature small heads, known as buttoning.
40°F Soil
Minimum temperature for seed germination.
Minimum temperature for seed germination.
65–85°F Soil
Optimum germination range; about 70–75°F is an excellent target.
Optimum germination range; about 70–75°F is an excellent target.
60–65°F Average Air
Ideal cool-season growing range for cole crops.
Ideal cool-season growing range for cole crops.
High Temperatures
Cauliflower is highly heat sensitive; heat can reduce curd quality and disrupt head formation.
Cauliflower is highly heat sensitive; heat can reduce curd quality and disrupt head formation.
Hot + Dry
Greater risk of water stress, stalled head development, and poor curd quality.
Greater risk of water stress, stalled head development, and poor curd quality.
Cool + Wet/Humid
Greater risk of downy mildew, clubroot, bacterial diseases, root problems, and cabbage maggot injury.
Greater risk of downy mildew, clubroot, bacterial diseases, root problems, and cabbage maggot injury.
Irregular Moisture
Water stress can reduce yield, firmness, head size, and color; maintain consistent soil moisture.
Water stress can reduce yield, firmness, head size, and color; maintain consistent soil moisture.
Harvest
Days to Maturity
80 days
80 days
Harvest Window
Spring: March 15 – May 31
Fall/Winter: October 15 – March 31
Spring: March 15 – May 31
Fall/Winter: October 15 – March 31
Harvest Indicators
Heads are firm, compact, dense, and typically about 4–8 inches in diameter, depending on cultivar. Harvest before individual florets begin separating, loosening, or developing a ricey appearance.
Heads are firm, compact, dense, and typically about 4–8 inches in diameter, depending on cultivar. Harvest before individual florets begin separating, loosening, or developing a ricey appearance.
Harvest Instructions
Cut the main stalk just below the head while it is firm and compact, leaving several wrapper leaves attached for protection. For white non-self-blanching cultivars, fold or loosely tie outer leaves over the developing head when it is about 2–3 inches across to reduce yellowing from sunlight. Harvest promptly once mature because overmature heads loosen and lose quality.
Cut the main stalk just below the head while it is firm and compact, leaving several wrapper leaves attached for protection. For white non-self-blanching cultivars, fold or loosely tie outer leaves over the developing head when it is about 2–3 inches across to reduce yellowing from sunlight. Harvest promptly once mature because overmature heads loosen and lose quality.
Crop Relationships
Crop Family
Brassicaceae — Mustard / Cabbage Family
Brassicaceae — Mustard / Cabbage Family
Crop Rotation Group
Brassicaceae / Cole Crops
Brassicaceae / Cole Crops
Companion Plants
Dill
Sage
Rosemary
Celery
Onions
Dill
Sage
Rosemary
Celery
Onions
Plants to Avoid
Tomatoes
Pole Beans
Runner Beans
Peppers
Strawberries
Tomatoes
Pole Beans
Runner Beans
Peppers
Strawberries
Helpful Links
- Zone 9 Planting Calendar: What to Plant All Year — Use the year-round calendar to plan cauliflower alongside other cool-season Zone 9 vegetables.
- Zone 9 Fall Planting Guide — Plan fall cauliflower and other cool-season vegetables as temperatures begin to decline.
- Zone 9 Winter Planting Guide — See how cauliflower fits into the productive Zone 9 winter garden.
- Zone 9 Spring Planting Guide — Plan an early spring cauliflower crop before warmer weather becomes limiting.
- What to Plant in September in Zone 9 — See when cauliflower and other fall vegetables can be started or transplanted as the fall season develops.
Data Sources & Methodology:
The crop data presented in this guide represents standardized Zone 9 values derived from and averaged across guidance from UF/IFAS Extension, Texas A&M AgriLife Extension, University of Arizona Cooperative Extension, and UC Agriculture & Natural Resources. USDA establishes the Zone 9 plant-hardiness framework. Recommendations may vary by local climate, cultivar, soil conditions, microclimate, and individual growing conditions.
The crop data presented in this guide represents standardized Zone 9 values derived from and averaged across guidance from UF/IFAS Extension, Texas A&M AgriLife Extension, University of Arizona Cooperative Extension, and UC Agriculture & Natural Resources. USDA establishes the Zone 9 plant-hardiness framework. Recommendations may vary by local climate, cultivar, soil conditions, microclimate, and individual growing conditions.
