Kale is a cold-hardy, resilient green that is one of the easiest brassicas to grow. With varieties like 'Red Russian' and 'Lacinato', kale offers diverse colors and textures, making it both nutritious and ornamental. Its flavor even improves with frost. Ideal for gardeners of all skill levels, kale thrives in cool weather and requires minimal care.
- Common Names: Curly Kale, Leaf Cabbage, Russian Kale
- Scientific Name: Brassica oleracea var. acephala
- Plant Type: Biennial plant
- Plant Height: 2-4 feet
- Growing Difficulty: Easy
- Growing Time: 8 weeks
- Bloom Time: Spring
- Temperature: Cool weather, tolerates frost
- Hardiness Zone: 2-11 (Find your hardiness zone here)
- Sunlight: Full Sun
- Soil pH: 5.5 to 6.5
- Watering Frequency: Keep soil consistently moist
- Plant Spacing: 12-18 inches apart
Different Methods to Grow Kale
Direct Seeding into the Soil
Seeds are planted directly into the garden soil. This method involves planting seeds 1/4 to 1/2 inch deep and 1 inch apart in rows 18 to 30 inches apart. Suitable for both spring and fall planting.
- Pros: Simple and cost-effective; seeds can germinate at low temperatures (40°F/4°C).
- Cons: Requires careful soil preparation and consistent watering; may be affected by pests and weather conditions.
Transplanting Start Plants from the Nursery
Young plants (transplants) are planted at the depth they were growing in the container. They should be spaced 12 inches apart in rows 18 to 30 inches apart. This method is ideal for getting a head start on the growing season.
- Pros: Faster start to the growing season; young plants are more resilient.
- Cons: More expensive than seeds; requires careful handling during transplanting.
Growing as a Winter Vegetable under Cover
Kale is grown under protective covers or in mild winter regions. This method can yield all winter long in regions like the Southwest, Pacific Northwest, and Southeast. Consultation with local cooperative extension for specific planting times is recommended.
- Pros: Extends the growing season; can yield throughout winter in suitable regions.
- Cons: Requires additional resources for covers; may need specific local knowledge for best results.
Ideal Soil and Location Requirements
For optimal growth, kale requires fertile, well-drained soil with a pH of 5.5 to 6.5. Full sun is ideal, but it can tolerate partial shade. Adding compost and nitrogen-rich amendments enhances soil fertility, ensuring robust plant development.
When to Plant Kale
Kale is best planted in early spring or fall. For spring planting, sow seeds 4 to 6 weeks before the last frost. For fall planting, direct-seed 3 months before the first fall frost. Kale thrives in cool weather and can withstand frost, which often enhances its flavor.
Growing Kale Outdoors
Growing kale outdoors in a garden is best achieved through direct seeding into the soil. This method is straightforward and cost-effective, making it accessible for home gardeners. Here’s a step-by-step guide to help you grow kale successfully:
- Prepare the soil. Add plenty of compost and nitrogen-rich amendments like blood meal or composted manure to enhance soil fertility.
- Choose the right time. For spring planting, sow seeds 4 to 6 weeks before the last frost. For fall planting, direct-seed 3 months before the first fall frost.
- Plant the seeds. Sow seeds 1/4 to 1/2 inch deep and 1 inch apart in rows 18 to 30 inches apart.
- Water well. After planting, water the soil thoroughly to ensure the seeds are well-hydrated.
- Thin the seedlings. Once the seedlings are about 2 weeks old, thin them to 8 to 12 inches apart to give each plant enough space to grow.
- Maintain moisture. Keep the soil consistently moist, providing about 1 to 1.5 inches of water per week.
- Fertilize as needed. Side-dress with a high-nitrogen fertilizer to support healthy growth.
- Mulch the soil. Apply mulch to retain moisture and keep the soil cool, which helps the plants thrive.
Growing Kale Indoors
Growing kale indoors is possible, but it requires careful attention to light, temperature, and watering. Here’s a step-by-step guide to help you grow kale indoors successfully:
- Choose the right container. Use pots that are at least 12 inches in diameter with good drainage holes.
- Prepare the soil. Fill the pots with a high-quality potting mix that is rich in organic matter and well-draining.
- Plant the seeds. Sow seeds about 1/4 inch deep and space them 1 inch apart.
- Provide adequate light. Place the pots in a location where they can receive at least 6 hours of direct sunlight daily. If natural light is insufficient, use grow lights.
- Maintain the temperature. Keep the indoor temperature around 70°F (21°C) during the day and slightly cooler at night.
- Water consistently. Keep the soil consistently moist but not soggy. Water when the top inch of soil feels dry.
- Thin the seedlings. Once the seedlings are about 2 weeks old, thin them to 8 to 12 inches apart to give each plant enough space to grow.
- Fertilize as needed. Use a balanced liquid fertilizer every 4 to 6 weeks to support healthy growth.
- Harvest the leaves. Begin harvesting when the leaves are about the size of your hand. Pick the outer leaves first, allowing the inner leaves to continue growing.
The chill of a moderate frost or light snow improves the flavor of kale. This hardy green can withstand very cold temperatures, making it an excellent choice for winter gardening in mild climates.
Caring for Kale
- Watering: Keep your kale well-watered, providing about 1 to 1.5 inches of water per week if rainfall is insufficient. Consistent moisture is key to healthy growth.
- Fertilizing: Side-dress with a high-nitrogen fertilizer as needed to support robust growth. Adding compost or nitrogen-rich amendments like blood meal can also be beneficial.
- Mulching: Apply mulch around your kale plants to retain soil moisture, suppress weeds, and keep the soil cool. After the first hard freeze, mulch heavily to ensure a supply of mature leaves through winter.
- Pest Management: Common pests include aphids, cabbageworms, and flea beetles. Use row covers to protect plants, handpick pests, and consider natural treatments like insecticidal soap or companion planting to deter unwanted insects.
- Harvesting: Begin harvesting when the leaves are about the size of your hand. Pick the outer leaves first, but avoid taking more than one-third of the plant at a time to maintain its productivity. A light frost can enhance the flavor, making the leaves sweeter.
Common Challenges With Kale
Kale is a very resilient plant, making it one of the easiest members of the brassica family to grow. It thrives in cool weather and can tolerate frost and even snow, which often enhances its flavor. Whether you're a seasoned gardener or a beginner, kale's hardy nature and minimal care requirements make it an excellent choice for your garden. In my experience, once you get the basics right, such as soil preparation and consistent watering, kale practically grows itself.
However, growing kale isn't without its challenges. Common pests like aphids, cabbage worms, and flea beetles can be a nuisance, and diseases such as black rot and powdery mildew may affect your plants. Hot temperatures can also slow growth and cause the leaves to become bitter. Ensuring adequate water and protecting your plants from extreme weather and pests are crucial steps to maintaining a healthy kale crop. Despite these challenges, the rewards of growing your own kale are well worth the effort.
Safety of Kale for Pets
Kale is not safe for cats, dogs, and other pets. If you suspect your pet has ingested kale and is showing symptoms of poisoning, contact the ASPCA 24-hour hotline immediately for assistance.
Frequently Asked Questions
Can kale grow in zones 9a - 9b?
Yes, kale can grow in zones 9a - 9b, but it may require some shade during the hottest part of the day. Planting in the fall allows the plants to mature in cooler weather, which is ideal for kale.
What is the difference between ornamental and edible kale?
Ornamental kale is bred for its vibrant colors and decorative appeal, while edible kale is selected for its taste and nutritional value. Although ornamental kale is technically edible, it is often more bitter and less tender than its culinary counterpart.
How can I use ornamental kale in landscaping?
Ornamental kale can be used in large groupings or as edging for garden beds. It pairs well with other fall colors and can be an attractive addition to window boxes and containers, providing a splash of color during cooler months.
Can I grow kale indoors?
Yes, kale can be grown indoors, but it requires adequate light, such as from grow lights, and consistent moisture. Indoor kale may not achieve the same robust growth as outdoor plants but can still provide fresh greens year-round.
