Vegetable Guide
Kale
Brassica oleracea var. sabellica (Acephala Group)
Kale is a hardy, cool-season leafy vegetable in the Brassicaceae, or mustard/cabbage family. Unlike cabbage, kale does not form a head; it produces an open rosette of leaves that may be curly, flat, blue-green, or purple depending on cultivar. Kale is highly cold tolerant, and leaf flavor and tenderness generally improve during cool weather.
Zone 9 is especially well suited to fall, winter, and early-spring kale production. UF/IFAS lists kale from August through February in North Florida, September through February in Central Florida, and September through January in South Florida. Arizona Extension recommends kale when soils are about 45–85°F and daytime temperatures are roughly 60–75°F, and notes that established kale tolerates cold well.
Sun
Full sun, 6–8+ hours daily; tolerates some light partial shade
Days to Maturity
50 days
Plant Type
Vegetable / Cool-Season Leafy Green
Planting Windows for Zone 9
| Stage | Spring | Fall |
|---|---|---|
| Start Indoors | Dec 15 – Jan 31 | Jul 15 – Aug 31 |
| Direct Sow | Jan 15 – Feb 28 | Aug 15 – Nov 15 |
| Transplant | Feb 15 – Mar 31 | Sep 1 – Nov 30 |
| Harvest | Mar 15 – May 31 | Oct 1 – Mar 31 |
Recommended Kale Varieties
Blue Ridge — Hybrid kale recommended by UF/IFAS for Florida production.
Darkibor — Curly hybrid kale recommended by UF/IFAS; vigorous with dark blue-green leaves.
Oldenbor — Curly hybrid kale recommended by UF/IFAS.
Starbor — Compact curly hybrid kale recommended by UF/IFAS.
Vates — Open-pollinated kale recommended by UF/IFAS; compact and cold tolerant.
Winterbor — Curly hybrid kale recommended by UF/IFAS; noted for strong cold tolerance and extended harvest.
Dinosaur (Lacinato type) — Recommended in Texas A&M planting guidance; long, dark, blistered leaves with good cool-season quality.
Fertilizer Schedule
Pre-Plant — 1–3 Weeks Before Planting
Incorporate finished compost or organic matter and apply fertilizer according to a soil test. If fertility is low and no test is available, use a modest balanced fertilizer before planting.
Incorporate finished compost or organic matter and apply fertilizer according to a soil test. If fertility is low and no test is available, use a modest balanced fertilizer before planting.
At Planting / Transplanting — Day 0
Set transplants at the same depth they were growing and water thoroughly. Use starter fertilizer only if needed and avoid concentrated fertilizer directly against roots or stems.
Set transplants at the same depth they were growing and water thoroughly. Use starter fertilizer only if needed and avoid concentrated fertilizer directly against roots or stems.
Early Growth — After Thinning or Once Transplants Are Established
Apply a light nitrogen side-dressing to support dark-green leafy growth.
Apply a light nitrogen side-dressing to support dark-green leafy growth.
Continued Leaf Growth — About 4–6 Weeks Later If Needed
Repeat a light side-dressing only if plants become pale or growth slows and insect damage is not responsible.
Repeat a light side-dressing only if plants become pale or growth slows and insect damage is not responsible.
Extended Harvest — Ongoing As Needed
Routine heavy feeding is unnecessary in well-prepared soil. Use only light supplemental fertilizer where prolonged harvest, sandy soil, or nutrient-leaching rainfall indicates a need.
Routine heavy feeding is unnecessary in well-prepared soil. Use only light supplemental fertilizer where prolonged harvest, sandy soil, or nutrient-leaching rainfall indicates a need.
Planting Details
Seed Depth
0.25–0.5 inches
0.25–0.5 inches
Plant Spacing
8–12 inches
8–12 inches
Row Spacing
18–24 inches
18–24 inches
Germination Time
4–7 days under favorable conditions
4–7 days under favorable conditions
Germination Temperature
65–70°F optimum; 45–85°F workable planting range
65–70°F optimum; 45–85°F workable planting range
Minimum Soil Temperature
45°F practical lower planting and germination limit
45°F practical lower planting and germination limit
Optimal Soil Temperature
65–70°F excellent germination and establishment target
65–70°F excellent germination and establishment target
Growing Requirements
Sun
Full sun, 6–8+ hours daily; tolerates some light partial shade
Full sun, 6–8+ hours daily; tolerates some light partial shade
Water
Consistent, deep watering; keep soil evenly moist without waterlogging, especially during rapid leaf production.
Consistent, deep watering; keep soil evenly moist without waterlogging, especially during rapid leaf production.
Soil
Fertile, well-drained loam or sandy loam rich in organic matter; avoid compacted or poorly drained soil.
Fertile, well-drained loam or sandy loam rich in organic matter; avoid compacted or poorly drained soil.
Soil pH
6.0–6.5
6.0–6.5
Fertilizer
Moderate-to-heavy nitrogen feeder for leafy growth; maintain balanced fertility and avoid excessive late applications.
Moderate-to-heavy nitrogen feeder for leafy growth; maintain balanced fertility and avoid excessive late applications.
Fertilizer Schedule
Preplant compost/soil-test fertilizer → starter fertilizer at transplanting if needed → light nitrogen side-dressing after thinning or once transplants are established → repeat in about 4–6 weeks only if plants become pale or growth slows → additional light feeding only if prolonged harvest, sandy soil, or nutrient-leaching rainfall indicates a need.
Preplant compost/soil-test fertilizer → starter fertilizer at transplanting if needed → light nitrogen side-dressing after thinning or once transplants are established → repeat in about 4–6 weeks only if plants become pale or growth slows → additional light feeding only if prolonged harvest, sandy soil, or nutrient-leaching rainfall indicates a need.
Top 5 Common Kale Pests
Imported Cabbageworm
Fall–Spring; active during mild weather
Velvety green caterpillars chew large irregular holes in leaves and may skeletonize foliage when numerous. Frass and caterpillars reduce the quality of harvested leaves.
Fall–Spring; active during mild weather
Velvety green caterpillars chew large irregular holes in leaves and may skeletonize foliage when numerous. Frass and caterpillars reduce the quality of harvested leaves.
Cabbage Looper
Fall–Spring
Green looping caterpillars chew ragged holes in leaves. Heavy populations can remove substantial leaf area and reduce harvest quality.
Fall–Spring
Green looping caterpillars chew ragged holes in leaves. Heavy populations can remove substantial leaf area and reduce harvest quality.
Diamondback Moth
Fall–Spring; often strongest during mild weather
Small green larvae feed mainly on leaf undersides, first creating translucent window-like patches and later small holes. Heavy infestations can leave foliage riddled with feeding damage.
Fall–Spring; often strongest during mild weather
Small green larvae feed mainly on leaf undersides, first creating translucent window-like patches and later small holes. Heavy infestations can leave foliage riddled with feeding damage.
Cabbage Aphid
Fall–Spring; often increases during cool mild weather
Dense gray-green aphid colonies form on young leaves and stems. Feeding causes curling, yellowing, stunting, and contamination of harvested foliage.
Fall–Spring; often increases during cool mild weather
Dense gray-green aphid colonies form on young leaves and stems. Feeding causes curling, yellowing, stunting, and contamination of harvested foliage.
Flea Beetles
Fall–Spring; greatest on seedlings and young transplants
Adults chew numerous small round shot holes in leaves. Heavy feeding can stunt or severely weaken young plants before they become established.
Fall–Spring; greatest on seedlings and young transplants
Adults chew numerous small round shot holes in leaves. Heavy feeding can stunt or severely weaken young plants before they become established.
Top 5 Common Kale Diseases
Black Rot
Warm, wet or humid conditions
Yellow V-shaped lesions develop from leaf margins toward the midrib and veins may darken. Severe infection causes leaf death, stunting, and systemic vascular discoloration.
Warm, wet or humid conditions
Yellow V-shaped lesions develop from leaf margins toward the midrib and veins may darken. Severe infection causes leaf death, stunting, and systemic vascular discoloration.
Clubroot
Cool-to-moderate moist soil; especially acidic or infested soil
Roots become enlarged, swollen, and club-shaped. Aboveground plants are stunted, yellow, and may wilt during warm parts of the day despite adequate soil moisture.
Cool-to-moderate moist soil; especially acidic or infested soil
Roots become enlarged, swollen, and club-shaped. Aboveground plants are stunted, yellow, and may wilt during warm parts of the day despite adequate soil moisture.
Downy Mildew
Cool, humid or wet weather; Fall–Spring
Irregular pale-yellow patches develop on upper leaf surfaces and white to gray fluffy growth can appear underneath. Severe infection causes browning, blighting, and loss of usable foliage.
Cool, humid or wet weather; Fall–Spring
Irregular pale-yellow patches develop on upper leaf surfaces and white to gray fluffy growth can appear underneath. Severe infection causes browning, blighting, and loss of usable foliage.
Alternaria Leaf Spot
Mild-to-warm humid weather with prolonged leaf wetness
Small dark circular spots enlarge and often develop concentric target-like rings. Severe infection causes leaf blighting and lowers the quality of harvested greens.
Mild-to-warm humid weather with prolonged leaf wetness
Small dark circular spots enlarge and often develop concentric target-like rings. Severe infection causes leaf blighting and lowers the quality of harvested greens.
White Rust
Cool, moist weather; often Fall–Spring
White raised pustules develop mainly on leaf undersides, while yellow spots may appear on upper surfaces. Heavy infection can distort leaves and reduce marketable or usable foliage.
Cool, moist weather; often Fall–Spring
White raised pustules develop mainly on leaf undersides, while yellow spots may appear on upper surfaces. Heavy infection can distort leaves and reduce marketable or usable foliage.
Zone 9 Weather Patterns
Kale is highly adapted to the cooler part of the Zone 9 growing season, with cool weather generally improving leaf sweetness and tenderness.
Below About 25°F
Young kale may be injured, but established plants are highly cold tolerant and often survive light freezes.
Young kale may be injured, but established plants are highly cold tolerant and often survive light freezes.
Around 32°F
Established kale tolerates frost well, and cool weather often improves sweetness and tenderness.
Established kale tolerates frost well, and cool weather often improves sweetness and tenderness.
45°F Soil
Practical lower planting/germination limit used in Arizona guidance.
Practical lower planting/germination limit used in Arizona guidance.
45–85°F Soil
Broad workable planting range in Arizona Extension guidance.
Broad workable planting range in Arizona Extension guidance.
65–70°F Soil
Excellent seed-germination target; UC ANR lists 65–70°F for kale germination.
Excellent seed-germination target; UC ANR lists 65–70°F for kale germination.
60–75°F Days / 45–55°F Nights
Favorable cool-season growth range.
Favorable cool-season growth range.
Above About 75–80°F
Growth can continue, but leaves may become tougher or more bitter and insect pressure can increase.
Growth can continue, but leaves may become tougher or more bitter and insect pressure can increase.
Hot + Dry
Greater risk of wilting, tough leaves, slower tender growth, and increased insect pressure.
Greater risk of wilting, tough leaves, slower tender growth, and increased insect pressure.
Cool + Wet/Humid
Greater risk of downy mildew, black rot, clubroot, Alternaria leaf spot, and white rust.
Greater risk of downy mildew, black rot, clubroot, Alternaria leaf spot, and white rust.
Irregular Moisture
Can reduce leaf quality and cause uneven growth; maintain consistent moisture for steady production.
Can reduce leaf quality and cause uneven growth; maintain consistent moisture for steady production.
Harvest
Days to Maturity
50 days
50 days
Harvest Window
Spring: March 15 – May 31
Fall/Winter: October 1 – March 31
Spring: March 15 – May 31
Fall/Winter: October 1 – March 31
Harvest Indicators
Leaves are full-sized for the intended use, deep green or cultivar-appropriate in color, tender, and free of major yellowing or toughness. Individual outer leaves can be harvested once they reach usable size while the center continues growing. Cool weather often improves sweetness and tenderness.
Leaves are full-sized for the intended use, deep green or cultivar-appropriate in color, tender, and free of major yellowing or toughness. Individual outer leaves can be harvested once they reach usable size while the center continues growing. Cool weather often improves sweetness and tenderness.
Harvest Instructions
Harvest the largest lower leaves first, leaving the central growing point and several younger leaves intact for continued production. Cut leaves cleanly near the stem. Baby leaves can be harvested young, while mature leaves are best picked before they become overly tough or yellow.
Harvest the largest lower leaves first, leaving the central growing point and several younger leaves intact for continued production. Cut leaves cleanly near the stem. Baby leaves can be harvested young, while mature leaves are best picked before they become overly tough or yellow.
Crop Relationships
Crop Family
Brassicaceae — Mustard / Cabbage Family
Brassicaceae — Mustard / Cabbage Family
Crop Rotation Group
Brassicaceae / Cole Crops
Brassicaceae / Cole Crops
Companion Plants
Sweet Alyssum
Dill
Cilantro
Calendula
Marigolds
Sweet Alyssum
Dill
Cilantro
Calendula
Marigolds
Plants to Avoid
Cabbage
Broccoli
Cauliflower
Collard Greens
Brussels Sprouts
Cabbage
Broccoli
Cauliflower
Collard Greens
Brussels Sprouts
Helpful Links
- Zone 9 Planting Calendar: What to Plant All Year — Use the year-round planting calendar to plan kale alongside other cool-season Zone 9 vegetables.
- Zone 9 Fall Planting Guide — See when kale and other cool-season vegetables fit into the Zone 9 fall garden.
- What to Plant in September in Zone 9 — Learn how kale fits into the transition from summer heat to fall production.
- Zone 9 Winter Planting Guide — Plan kale and other cold-tolerant vegetables for the productive Zone 9 winter season.
- Transition Your Garden From Summer Heat to Fall Production — Prepare beds and rotate crops before planting kale and other fall vegetables.
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.
