Kale Blue Curled

Kale is a nutritious leafy green vegetable from the Brassica family, valued for its rich flavor, tender leaves, and excellent versatility in the kitchen. It can be grown in garden beds, raised beds, containers, indoor microgreen trays, and carefully sprouted in jars. Kale is a cool-season crop that can tolerate light frost, and its flavor often becomes sweeter after exposure to cool weather.

Best Growing Conditions

• Light: Full sun is best, but kale can tolerate partial shade, especially in warmer climates.
• Soil: Fertile, well-draining soil rich in organic matter is ideal.
• Water: Keep soil evenly moist for tender leaves and steady growth.
• Temperature: Kale grows best in cool to mild weather and can tolerate light frost.
• Growth Habit: Leafy brassica vegetable that produces harvestable outer leaves over a long season.

Preparing for Growing

• Selecting a Planting Location: Choose a sunny garden bed, raised bed, or container location that receives at least 6 hours of light per day.
• Soil Preparation: Loosen the soil and mix in compost or aged organic matter before planting.
• Soil Quality: Kale grows best in fertile, moisture-retentive soil that drains well. Avoid compacted or waterlogged soil.
• Container Preparation: If growing in containers, use pots with drainage holes and a quality potting mix enriched with compost.
• Season Planning: Kale performs best in spring and fall, but it can also be grown through cool parts of winter in mild climates.

Starting Kale from Seeds Indoors

• When to Start: Start seeds indoors about 4-6 weeks before transplanting outdoors for a spring crop. For a fall crop, start seeds in midsummer and transplant when temperatures begin to cool.
• Seed Preparation: No special seed preparation is needed. Kale seeds can be sown dry.
• Choosing Containers: Use seed trays, cell packs, or small pots filled with seed-starting mix.
• Sowing Indoors: Plant seeds about ¼-½ inch deep and keep the soil evenly moist until germination.
• Light: Place seedlings under grow lights or in a very bright location to prevent weak, stretched growth.
• Thinning: If multiple seedlings sprout in one cell, thin to the strongest seedling.
• Transplanting to Larger Containers: If seedlings become crowded before outdoor planting, move them into larger pots to support healthy root growth.
• Hardening Off: Before transplanting outdoors, gradually expose seedlings to outdoor conditions over several days.

Direct Sowing Outdoors

• When to Sow: Sow kale seeds outdoors in early spring as soon as the soil can be worked, or in late summer for a fall crop.
• Planting Depth: Sow seeds about ¼-½ inch deep.
• Seed Spacing: Sow seeds about 1 inch apart at first, then thin as seedlings grow.
• Final Plant Spacing: Thin or transplant kale plants to about 12-18 inches apart, depending on desired plant size.
• Row Spacing: Space rows about 18-24 inches apart, or allow enough room for mature plants in raised beds.
• Moisture: Keep the seedbed evenly moist until seedlings are established.
• Protection: Row cover can help protect young plants from cabbage worms, flea beetles, and other common brassica pests.

Growing Kale in Containers or Pots

• Container Size: Use a container at least 8-12 inches deep for baby greens or at least 12 inches deep and wide for larger mature kale plants.
• Drainage: Make sure containers have drainage holes to prevent soggy soil.
• Soil: Use a rich, well-draining potting mix. Mixing in compost can help support strong leaf production.
• Sowing or Transplanting: Sow seeds directly in the container or transplant young seedlings once they have several true leaves.
• Spacing: Grow one mature kale plant per medium container, or space multiple plants 12-18 inches apart in larger planters.
• Watering: Container-grown kale dries out faster than garden-grown plants, so check soil moisture regularly.
• Feeding: Use compost-rich soil and apply a balanced fertilizer as needed to support continuous leaf growth.
• Placement: Place containers in full sun during cool weather. In warmer climates, light afternoon shade can help prevent stress.

Growing Kale Microgreens in Containers

Kale seeds can be grown as fresh, tender microgreens with a mild brassica flavor. Kale microgreens are easy to grow indoors and work well for small spaces, kitchen gardening, and year-round fresh greens. They can be used in salads, sandwiches, wraps, bowls, smoothies, soups, eggs, and fresh garnishes.

• Container: Use a shallow tray or container about 1-2 inches deep with drainage holes. Place a solid tray underneath to catch excess water.
• Growing Medium: Fill the tray with seed-starting mix, coconut coir, or another clean microgreen growing medium. Moisten the medium before sowing.
• Seed Preparation: Kale seeds do not need soaking for microgreens.
• Sowing: Sprinkle seeds evenly across the surface. Sow densely, but avoid piling seeds on top of each other.
• Covering: Press seeds gently into the moist medium and cover the tray with another tray, lid, or breathable cover for the first 2-4 days to encourage even germination.
• Moisture: Mist gently or bottom-water as needed. Keep the medium moist but not soggy.
• Light: Once seeds sprout, remove the cover and place the tray under grow lights or near a bright window.
• Airflow: Good airflow helps prevent mold and keeps the crop healthy.
• Harvest Time: Kale microgreens are usually ready in about 8-14 days, depending on temperature, light, and growing conditions.
• How to Harvest: Use clean scissors to cut the microgreens just above the growing medium when they are a few inches tall and have opened their seed leaves.
• Best Uses: Add kale microgreens to salads, sandwiches, wraps, grain bowls, smoothies, omelets, soups, and fresh garnishes.

Sprouting Kale Seeds in Jars

Kale seeds can also be sprouted in jars. Kale sprouts are harvested very young and grown without soil, so cleanliness, airflow, rinsing, and complete drainage are very important. For best results, use clean, untreated seeds intended for edible sprouting or microgreen use.

• Supplies Needed: Use a clean wide-mouth glass jar, a sprouting lid or cheesecloth, a rubber band or jar ring, and fresh drinkable water.
• Seed Amount: Add about 1-2 tablespoons of kale seeds to the jar. Do not overfill, because sprouts expand as they grow.
• Initial Rinse: Rinse seeds thoroughly with cool water before soaking.
• Soaking: Soak seeds for about 6-8 hours, then drain completely.
• Draining: After soaking, place the jar upside down at an angle so excess water can drain and air can circulate.
• Rinsing Schedule: Rinse and drain 2-3 times per day. Make sure no standing water remains at the bottom of the jar.
• Airflow: Keep the jar in a well-ventilated area away from direct sunlight during early sprouting.
• Light: Once small leaves appear, place the jar in indirect light for several hours to help the sprouts green up.
• Harvest Time: Kale sprouts are usually ready in about 3-6 days, depending on temperature and growing conditions.
• Final Rinse: Rinse thoroughly before eating and drain very well.
• Storage: Store finished sprouts in a clean container in the refrigerator and use them soon for best freshness.

Important Sprout Safety Tips

• Use Suitable Seeds: Use clean, untreated seeds intended for edible sprouting or microgreen use.
• Keep Everything Clean: Wash hands, jars, lids, trays, and surfaces before handling seeds or sprouts.
• Use Clean Water: Always rinse with fresh drinkable water.
• Drain Completely: Sprouts should stay moist, not waterlogged. Standing water can increase spoilage risk.
• Watch for Problems: Do not eat sprouts that smell unpleasant or appear slimy, moldy, or discolored.
• Refrigerate Promptly: Keep harvested sprouts refrigerated in a clean container.
• Extra Safety Note: Raw sprouts can carry food safety risks. People who are pregnant, elderly, very young, or immunocompromised should be especially cautious with raw sprouts.

Transplanting Kale to the Garden

• Site Preparation: Prepare a sunny planting area with fertile, well-draining soil. Mix in compost before planting.
• Timing: Transplant kale during cool weather. Avoid transplanting during extreme heat.
• Seedling Size: Transplant when seedlings have several true leaves and a healthy root system.
• Spacing: Space plants about 12-18 inches apart, depending on variety and desired leaf size.
• Planting Depth: Set transplants at the same depth they were growing in the tray, or slightly deeper if they are leggy, but do not bury the growing point.
• After Transplanting: Water thoroughly and keep soil evenly moist while plants establish.
• Mulching: Add a light layer of mulch to conserve moisture, suppress weeds, and keep soil temperatures more stable.

Plant Care

• Watering: Provide consistent moisture throughout the growing season. Dry soil can make leaves tougher and more bitter.
• Fertilizing: Kale benefits from fertile soil and steady nutrition. Use compost or a balanced fertilizer as needed during active growth.
• Weeding: Keep the growing area weed-free to reduce competition for nutrients and water.
• Mulching: Mulch helps retain moisture, reduce weeds, and keep roots cooler during warm weather.
• Pest Management: Watch for cabbage worms, aphids, flea beetles, and slugs. Row cover can help protect young plants.
• Disease Prevention: Provide good spacing and airflow. Avoid overhead watering when possible to reduce leaf disease pressure.
• Heat Stress: Hot weather can slow growth and reduce leaf quality. In warm climates, provide afternoon shade and consistent water.
• Cold Weather: Kale can tolerate light frost, and cool weather may improve flavor.

Harvesting Kale

• When to Harvest: Begin harvesting when leaves reach the desired size. Baby leaves can be harvested young, while mature leaves are usually ready when they are about 8-12 inches long.
• Harvest Method: Cut or snap off the outer leaves first, leaving the center growing point intact so the plant can continue producing.
• Continuous Harvest: Harvest regularly to encourage new leaf growth and keep plants productive.
• Best Time of Day: Harvest in the morning when leaves are crisp and hydrated.
• Storage: Store harvested kale in the refrigerator in a breathable bag or container. Use within several days for best flavor and texture.

When to Start Kale by USDA Plant Hardiness Zone

• Zones 1-3: Start seeds indoors 6-8 weeks before the last frost date for a spring crop. Sow again in midsummer for a fall harvest.
• Zones 4-6: Start indoors in early spring or direct sow outdoors when soil can be worked. Plant again in late summer for fall and early winter harvests.
• Zones 7-8: Grow kale in spring and fall. Fall planting often gives the best flavor and harvest quality.
• Zones 9-10: Kale usually performs best as a fall, winter, or early spring crop. Avoid the hottest part of summer unless growing with shade and steady moisture.
• Zone 11: Grow kale during the coolest months of the year. Provide afternoon shade and consistent water if temperatures rise.

Fast Facts

• Botanical Name: Brassica oleracea var. acephala
• Common Name: Kale
• Plant Type: Cool-season leafy green vegetable
• Planting Depth: ¼-½ inch
• Seed Spacing: About 1 inch, then thin as needed
• Final Plant Spacing: 12-18 inches
• Row Spacing: 18-24 inches
• Container Depth: At least 8-12 inches for regular kale; 1-2 inches for microgreens
• Seeds per Pot: 2-3 seeds per small pot, then thin to the strongest seedling
• Water Preferences: Evenly moist soil; avoid waterlogging
• Sun Preferences: Full sun to partial shade
• Soil Type: Fertile, well-draining soil rich in organic matter
• Soil pH: About 6.0-7.5
• Temperature Preference: Cool to mild weather, generally around 45°F to 75°F
• Days to Germination: About 5-10 days under good conditions
• Days to Harvest: About 50-70 days from seed, or 30-50 days from transplanting, depending on variety and harvest size
• Microgreens Harvest: About 8-14 days
• Sprouts Harvest: About 3-6 days
• Companion Plants: Onions, celery, dill, chamomile, mint, lettuce, beets, and other cool-season crops