8+ Must-Know Tips and Tricks for Growing Kale

When you think of superfoods, kale might be one of the first veggies that come to mind. It’s an incredibly nutritious leafy green vegetable, and it’s also super easy to grow. Discover all the essential tips for growing kale at home and enjoy a continuous harvest of fresh kale leaves.

Both kale and cabbage get classified under the botanical name Brassica oleracea. The two crops are closely related. Kale belongs to the acephala group of the Brassica plant family, which means it doesn’t produce a central head like cabbage. The leaves often get used similarly to other cooking greens like Swiss chard and collards.

Kale leaves have an earthy, mildly bitter flavor. The younger leaves are milder-tasting and more tender. They’re an excellent addition to fresh salads, stir-fries, and soups. If you want to add spring and fall veggies to your garden, why not try growing a few kale plants?

Expert Advice for Growing Kale

Kale is a cool-season crop that grows best when temperatures are around 65-75℉. Most varieties of kale can withstand temperatures down to 20℉, but they tend to get bitter and tough in hot weather. Kale leaves usually taste sweeter after a light frost.

Kale plants have a biennial life cycle. They form their leaves and roots in the first year and grow flowers and seeds in their second growing season. However, since it tends to bolt when temperatures rise above 80℉ for extended periods, kale often gets treated like an annual crop.

In most regions, kale makes an ideal spring and fall crop. In zones with mild winters, the plants will continue producing edible leaves all winter. The plants go dormant during freezing winters, but the root system often survives, and new leaves sprout the following spring.

Plant kale in well-draining soil that’s rich in organic matter. Kale plants flourish in full sun to partial shade. Keep the soil consistently moist but never waterlogged. Give your kale plants an inch or two of water per week, depending on rainfall levels. Applying a generous layer of mulch over your garden soil helps protect against erosion, retain moisture, and suppress weed growth.

How Long Does Kale Take to Grow?

Are you wondering, “How long does kale take to grow?” Kale is a fast-growing plant. The leaves are ready to eat within 30-40 days from planting. When growing kale from seeds, expect about 55-75 days before your first harvest.

There are numerous kale cultivars to choose from, with flat or curly and green or purple leaves. Keep a few vital factors in mind when selecting your kale varieties: your area’s typical frost dates, days to maturity, and your intended culinary uses. Here are several of the best types of kale for home gardens.

Top Kale Varieties

• Lacinato/Tuscan (heirloom, 2-3 feet tall, smooth deep blue-green leaves, high yields, 60-65 days to maturity)
• Redbor (hybrid, 1-2 feet tall, curly purple leaves, frost-tolerant, 50-60 days to harvest)
• Red Russian (heirloom, 2-3 feet tall, smooth green leaves with purple stems, disease-resistant, 60 days to maturity)
• Scarlet (heirloom, 2-3 feet tall, curly purple leaves, heat-tolerant, 55 days to maturity)
• Vates (heirloom, 12-16 inches tall, curly blue-green leaves, heat-tolerant, 55 days to maturity)
• Winterbor (hybrid, 2-3 feet tall, curly blue-green leaves, frost-tolerant, 65 days to maturity)

Growing Kale from Seeds

Start kale seeds indoors in late winter or early spring if you have a short growing season. The seedlings are ready to transplant outdoors three to four weeks before your expected last frost date. Otherwise, direct-sow kale seeds in your veggie garden whenever the soil temperature exceeds 45℉. Plant a second kale crop for a fall harvest 12-14 weeks before your first autumn frost.

Seed Starting Supplies

• Organic kale seeds
• Seed-starting potting soil
• Seedling tray, peat pots, or a repurposed cardboard egg carton
• Humidity dome
• Clean spray bottle

Fill your seedling tray, peat pots, or an egg carton with a nutrient-rich potting mix. It’s helpful to pre-moisten the soil to avoid disturbing the seeds after planting. Press the kale seeds a quarter-inch deep and gently cover them with soil. Cover it with a humidity dome wrap to hold in moisture.

Kale seeds germinate fastest between 65-70℉. Germination typically takes five to eight days.

Once the seedlings sprout, move the tray to a sunny location where they’ll receive at least six hours of bright light daily. Or, place them under grow lights to keep the seedlings from growing elongated or “leggy.”

Transplant your kale seedlings outdoors a few weeks before your average last frost date. They can withstand a light frost but need protection with a cold frame or floating row covers if temperatures drop below 20℉.

Spacing between kale plants should be approximately 12 inches. Check the seed packet for variety-specific planting recommendations.

Growing Kale in Containers

If you don’t have space for a garden plot or raised beds at home, don’t worry. Kale is an ideal candidate for container gardens, too. Grow kale in pots on your deck, patio, porch, or indoors.

Container-grown kale plants often require a little more care than those planted in the ground. Potted plants tend to dry out faster and may require more frequent fertilization. This is because nutrients drain out of the soil along with excess water. In general, water your kale pots when the top inch or two of soil is completely dry. Fertilize your potted kale plants every four to six weeks throughout the growing season.

Once the weather gets cold in late fall, move the pots next to a wall of your house if possible. The radiant heat will keep them growing longer.

Best Soil and Fertilizer for Kale Plants

Kale grows best in moist, nutrient-rich soil. When growing kale in containers, use a potting blend with added perlite for drainage and peat moss or coconut coir for moisture retention.

The optimal soil pH level is slightly acidic, between 6.5 and 6.8. Acidic soil inhibits clubroot, a common fungal disease that affects Brassica plants. Overwatering and poor drainage increase the risk of plant diseases.

For the best possible results, add organic fertilizer or compost to your planting area a week or two ahead of time. In most cases, this is only necessary every few years. Contact your local extension service for a soil test to determine which nutrients you need. Overfertilizing damages the soil microbiome and inhibits plants’ roots from absorbing certain nutrients from the earth.

There are three primary macronutrients found in plant fertilizer: nitrogen (N), phosphorus (P), and potassium (K). Nitrogen enhances leafy growth, phosphorus encourages healthy root systems, and potassium boosts fruiting and flowering processes. Choose a fertilizer high in nitrogen for growing leafy greens like arugula, cabbage, Swiss chard, kale, lettuce, or spinach.

Slow-release granular fertilizers are usually more effective over long periods than liquid fertilizers. Additionally, scatter used coffee grounds around the plant’s base to add extra nitrogen to the soil and slightly lower the pH level. Mulching with abrasive materials like coffee grounds and crushed eggshells also deter pests like slugs and snails.

Harvesting and Storing Homegrown Kale

Kale leaves have the sweetest flavor after a light frost. However, they’ll be perfectly edible and delicious in late spring and early summer. The leaves turn bitter and tough when temperatures are consistently over 80℉. Give summer kale plants a bit of shade to extend your growing season.

Harvest baby kale greens within 30 days of transplanting. Wait 50-70 days before harvesting for larger leaves. Always use sterile, sharp clippers to avoid accidentally damaging the main stem.

Clip the outermost leaves first to encourage the plant to keep producing new growth. Avoid taking more than half of the leaves at one time. The plant must create enough energy through photosynthesis to keep growing.

Store fresh kale in the fridge with the stems submerged in a glass of water like a flower bouquet. Or, wrap them in damp paper towels. That way, kale leaves stay fresh for up to two weeks.

For longer shelf life, you can also freeze kale. Unblanched, frozen kale lasts four to six weeks. With blanching, it will keep for up to one year. Use your frozen kale as soon as possible to retain the best possible flavor and texture.

Resolving Common Pest and Disease Issues

Although kale is usually low-maintenance, there are a few pest and disease problems to watch out for. Plants are much more vulnerable to attacks from insects and pathogens when stressed. Providing appropriate sunlight, water, and fertilizer is their best defense.

Aphids, cabbage worms, cabbage loopers, flea beetles, root-knot nematodes, and cutworms are some of the most prevalent insects that feed on kale plants. They damage the plants’ leaves, stems, and roots and sometimes kill young seedlings.

Spray all plant parts (especially the undersides of the leaves) with an organic insecticide like horticultural oil, insecticidal soap, or neem oil to kill aphids and flea beetles on contact. Diatomaceous earth eliminates cabbage loopers, cabbage worms, and cutworms, which are moth larvae. Another option is an organic biological pesticide like Bt (Bacillus thuringiensis) – a species of bacteria naturally found in soil. It secretes specific proteins that are toxic to most types of caterpillars, including cabbage worms, cabbage loopers, and cutworms.

Kale plants sometimes suffer from fungal diseases like powdery and downy mildew, which spread quickly in cool, wet conditions. Powdery mildew appears as white, fuzzy fungal growth on leaves and stems. Downy mildew first presents with yellow blotches that have brown edges and greyish-purple spores underneath.

Treat both diseases with an organic copper or sulfur fungicide. To avoid problems with fungal infections, avoid overwatering, provide ample airflow, and water with a soaker hose or drip irrigation to keep the plants’ leaves dry.

Companion Planting with Kale

Companion planting is a time-tested, sustainable garden design strategy that utilizes mutually beneficial interactions between certain plants. Some attract beneficial insects and repel pests. Certain plant pairings enhance flavor and overall growth.

However, a few plants inhibit each other’s growth and must live in separate areas. Remember, fennel doesn’t have friends! It secretes a growth-inhibiting chemical from its roots. Plant fennel in a pot or a faraway corner of your garden.

Legumes like beans and peas make outstanding companions for leafy green veggies. They fix atmospheric nitrogen into the surrounding soil through a unique relationship with soil bacteria. To learn more about this fascinating process, check out this article from the University of New Mexico.

Aromatic herbs like caraway, cilantro, dill, and tansy attract beneficial predatory insects like hoverflies, ladybugs, and parasitic wasps (which don’t sting humans.) Basil, mint, rosemary, and sage deter pests with their strong scent.

Alliums like chives, garlic, and onions are wonderful pest repellents. They ward off aphids, cabbage worms, carrot flies, spider mites, and slugs. However, keep them away from legumes. These two plant groups will stunt one another’s growth.

Flowers like borage, cosmos, and marigolds are excellent for attracting pollinators to the garden. In addition, they’re also practical for pest control. French marigolds secrete a natural chemical that kills root-knot nematodes when they feed, reducing the overall population. They also repel aphids and mosquitoes. Borage and cosmos attract predatory insects that feed on garden pests.

Avoid planting crops susceptible to similar problems close together. For example, grow other cabbage family members in a different location. Strawberries must also live elsewhere, as they often attract slugs that quickly devastate your kale leaves.

Kale is a delicious and nutritious vegetable that’s super simple to grow in your home garden. As a cool weather crop, kale grows best in the spring and fall. In climates with mild winters, it’s possible to grow kale year-round. This leafy green veggie is also great for container gardens. Growing kale alongside other veggies and herbs creates a healthy, interactive, and sustainable garden ecosystem.

Do you have any recommendations or questions about growing kale? Please share them in the comments! If you found these gardening tips beneficial, please share this post about how to grow kale with your fellow gardening enthusiasts.