Kale has become a superstar of the modern kitchen, celebrated for its nutritional powerhouse of vitamins, minerals, and antioxidants. While most gardeners grow kale as an annual, there’s a perennial variety that keeps producing fresh, nutrient-rich leaves year after year with minimal effort. By learning to grow perennial kale, you can enjoy continuous harvests, save on seeds, and create a sustainable, low-maintenance garden.
This guide will walk you through everything you need to know to plant, care for, and maintain perennial kale, ensuring a bountiful supply for your kitchen season after season.
1. Understanding Perennial Kale
Perennial kale differs from traditional annual kale varieties in that it does not die after one growing season. Some of the most popular perennial kales include:
- Daubenton Kale: Hardy and frost-tolerant, with curly leaves.
- Tree Kale (Brassica oleracea var. acephala, also called “Walking Stick Kale”): Can grow up to 6 feet tall over several years.
- Sea Kale (Crambe maritima): Tolerates coastal conditions and produces edible shoots and leaves.
Unlike annual kale, which must be replanted every year, perennial kale develops deep roots that help it survive through winters and droughts, allowing for a continuous harvest with proper care.
2. Choosing the Right Location
Perennial kale thrives in full sun but can tolerate partial shade. To maximize leaf production and plant health, follow these guidelines:
- Sunlight: 6–8 hours of direct sunlight per day.
- Soil: Fertile, well-draining soil rich in organic matter.
- Space: Allow at least 18–24 inches between plants to encourage airflow and prevent disease.
- Climate: While hardy varieties survive frost, they perform best in regions with mild winters and cool summers.
Planting in a raised bed or container is also an excellent option for controlling soil quality and drainage.
3. Preparing the Soil
Healthy kale begins with healthy soil. Perennial kale prefers slightly acidic to neutral soil (pH 6.0–7.0) with good fertility.
Steps to Prepare Soil:
- Clear the area of weeds and debris.
- Loosen the soil to a depth of 12–18 inches to accommodate deep roots.
- Amend with compost or well-rotted manure for long-term nutrient supply.
- Optional: Add a handful of balanced organic fertilizer to support early growth.
Perennial kale’s deep root system will access nutrients more efficiently over time, but starting with nutrient-rich soil gives plants a strong foundation for years of productivity.
4. Planting Perennial Kale
You can grow perennial kale from seeds or transplants, depending on your preference and timeline:
- Seeds: Start indoors 6–8 weeks before the last frost. Sow seeds ¼ inch deep in seed-starting mix, keeping soil moist.
- Transplants: Purchase young plants from nurseries for quicker establishment.
Planting Tips:
- Space seedlings 18–24 inches apart to prevent overcrowding.
- Water immediately after planting to help roots establish.
- Mulch around the base to retain moisture and regulate soil temperature.
For varieties like Tree Kale, consider staking or support as the plant grows taller over the years.
5. Watering and Fertilizing
Perennial kale prefers consistent moisture, but overwatering can lead to root rot or fungal diseases.
- Watering: Provide about 1–1.5 inches of water per week. Water at the base to avoid wetting foliage, which can encourage disease.
- Mulching: Apply organic mulch (straw, leaves, or compost) to conserve moisture and suppress weeds.
- Fertilizing: Use a balanced, slow-release fertilizer in early spring. Side-dress with compost or organic fertilizer mid-season to encourage leafy growth.
Healthy, nourished plants are more resilient and productive, producing tender leaves for years.
6. Pruning and Harvesting
Proper harvesting encourages continuous growth.
- Harvest outer leaves first: Begin picking once leaves reach 6–8 inches in length.
- Leave inner leaves and growing tips: This ensures the plant continues producing.
- Regular trimming: Prevents plants from becoming leggy and encourages denser foliage.
Perennial kale can produce leaves year-round in mild climates. In colder areas, harvest until the first hard frost, then allow plants to rest or cover with frost cloths for extended productivity.
7. Pest and Disease Management
Perennial kale is generally hardy but can attract pests common to brassicas, such as cabbage worms, aphids, and flea beetles.
Tips for Prevention and Management:
- Inspect plants regularly and remove pests by hand when possible.
- Use floating row covers to protect young leaves from insects.
- Encourage beneficial insects like ladybugs to naturally control aphids.
- Practice crop rotation to reduce disease risk, especially in raised beds.
Diseases like powdery mildew and downy mildew can be minimized with good airflow, proper spacing, and watering at the soil level.
8. Overwintering Perennial Kale
One of the most significant advantages of perennial kale is its cold tolerance. Here’s how to help your plants survive winter:
- Apply a thick layer of mulch around the base to insulate roots.
- Consider row covers or cloches for extra protection in extremely cold climates.
- Some varieties, like Daubenton and Sea Kale, are hardy to USDA zones 4–9, while tropical Tree Kale may need indoor relocation in harsh winters.
Even during dormant periods, the root system remains alive, ready to produce new leaves as soon as temperatures rise.
9. Companion Planting for Better Growth
Pairing perennial kale with compatible plants can boost growth, improve soil health, and reduce pest problems.
- Good companions: Beets, onions, garlic, mint, and aromatic herbs like rosemary or thyme.
- Avoid planting near: Tomatoes, strawberries, and pole beans, which may compete for nutrients or attract pests.
Companion planting creates a balanced ecosystem in your garden, helping kale thrive for years.
10. Propagating for Expansion
Perennial kale can be propagated to expand your garden or share with friends:
- Division: Carefully separate clumps of established plants in early spring.
- Stem cuttings: For varieties like Tree Kale, cut a healthy stem, remove lower leaves, and root in soil or water.
- Seeds: Collect seeds from mature plants after flowering for future planting.
Propagation ensures you have a continuous supply of kale while maintaining the genetic diversity of your collection.
11. Benefits of Growing Perennial Kale
Growing perennial kale is environmentally sustainable, economical, and nutritious:
- Sustainability: Reduces the need for yearly replanting and seed purchases.
- Nutrition: Kale leaves are rich in vitamins A, C, K, calcium, and antioxidants.
- Convenience: A perennial plant supplies fresh leaves whenever needed.
- Aesthetic: Dense, green foliage enhances garden beauty throughout the year.
A well-established perennial kale bed becomes a long-term asset, supplying the family with a reliable and healthy food source.
12. Tips for Long-Term Success
To ensure your perennial kale continues producing year after year, follow these key tips:
- Regular care: Water, mulch, and fertilize consistently.
- Monitor pests and diseases: Early detection prevents severe damage.
- Harvest strategically: Avoid removing too much foliage at once.
- Rotate soil amendments: Refresh the soil with compost annually to replenish nutrients.
- Document growth: Note seasonal patterns to adjust care for optimal harvest.
With proper attention, perennial kale can become a mainstay of your home garden for decades, offering both aesthetic and nutritional benefits.
Conclusion: A Garden That Gives Back Year After Year
Growing perennial kale is a rewarding venture for gardeners seeking sustainability, nutrition, and continuous harvests. Unlike annual varieties, perennial kale establishes a long-lasting presence in your garden, providing fresh leaves year-round with minimal effort.
By understanding your plant’s needs, selecting the right location, managing soil and water, and practicing consistent care, you can enjoy lush, healthy kale that keeps giving season after season. Whether you’re an experienced gardener or a beginner, perennial kale offers an eco-friendly, nutritious, and aesthetically pleasing addition to any garden, making it one of the most valuable plants for long-term cultivation.