Planting and Growing Kale: Sowing, Care and Harvesting

Jun 17, 2021by David Schulze

Kale is a productive cool-season crop that lets you harvest a few leaves at a time instead of pulling the whole plant. Grow it for tender baby leaves, larger cooking greens or a mix of colors and textures in the vegetable garden.

David will be the first to admit that kale is not his favorite thing to eat. Stir-frying it or adding it to a dish with ground beef makes it more appealing to him. Even so, he enjoys growing it, and plenty of gardeners appreciate a crop that keeps supplying fresh greens through cool weather.

Choose Kale for the Harvest You Want

Kale comes in curly, frilled and flatter-leaved forms, with foliage ranging from green and blue-green to purple shades. Lacinato types have distinctive long, textured leaves, while other varieties have more deeply divided or ruffled foliage.

Many varieties can be harvested young or grown for full-size leaves. Do not assume that every open-pollinated variety is for baby greens or every hybrid is only for mature harvest. Check the individual variety's description for its intended use, mature size and days to harvest.

Compare our Kale Seeds and choose a variety suited to your growing space and kitchen.

When to Plant Kale

Kale generally grows best in cool conditions. Depending on your region, it can be planted for spring, fall or winter harvest. In many Texas gardens, fall planting is especially useful because plants can develop as the weather becomes cooler.

Use your county Extension planting calendar and the seed packet to plan sowing. A fixed instruction to plant three months before frost is not suitable everywhere. Consider the variety's growth rate, local heat and how much time plants will have to establish before severe cold.

Established kale often tolerates frost, and cool weather can improve its flavor. Young plants and plants suddenly exposed to a hard freeze may be more vulnerable. Cold tolerance varies by variety, plant condition and the duration of the weather event, so do not treat kale as freeze-proof.

Prepare a Sunny, Well-Drained Bed

Choose a sunny site with fertile, well-drained soil. Some afternoon shade may help during warm conditions, but too much shade can slow growth. Remove weeds and prepare the bed so water can soak into the root zone without leaving it saturated.

Use a soil test to guide amendments and fertilizer. Kale benefits from adequate nutrition, but repeated feeding without considering the soil and product can waste money or damage plants.

Starting Kale Seeds Indoors

Use clean containers with drainage. Fill them with an appropriate seed-starting mix and moisten it evenly before sowing.
Follow packet depth. About 1/4 inch is common for kale, but the variety's directions are your starting point. Cover gently.
Provide suitable moisture. Bottom watering can help wet the mix without disturbing seed. Let the pots absorb water, then drain the excess rather than leaving them continuously standing in a half-full tray.
Give seedlings enough light. Use a suitable bright growing area or grow lights. Thin crowded seedlings and avoid stretching caused by inadequate light.
Water gently as needed. A fine, careful top watering does not automatically kill seedlings. Use whichever method keeps the mix evenly moist without waterlogging or washing it away.

Harden Off and Transplant

Gradually introduce indoor-grown seedlings to outdoor sun, wind and temperature changes before transplanting. Begin with sheltered exposure and increase it as the plants adjust, protecting them from damaging weather.

Choose sturdy seedlings with several true leaves and a healthy root system. Readiness is not determined by reaching exactly eight inches tall; smaller, compact plants can transplant well before that point.

Follow the variety's spacing instructions. Full-size kale commonly needs considerably more room than a densely sown baby-leaf crop. Set plants into prepared soil, water them in gently and keep the growing point above the soil.

See our hardening-off guide for more detail. Local temperatures, soil conditions and plant readiness should guide transplanting rather than a moon-phase calendar.

Direct Sowing Kale

Direct sowing works well when soil conditions and seasonal temperatures are suitable. Prepare a fine seedbed, sow at the packet's depth and water gently. Keep the seed zone from drying out while seedlings establish, without making it soggy.

Thin seedlings to the recommended final spacing. Crowding mature plants can make watering, inspection and harvesting more difficult. For baby greens, use the variety's baby-leaf guidance instead of automatically applying full-size plant spacing.

A fall sowing can be challenging if soil and air are still very hot. Adjust the timing or start transplants in an appropriate protected setting rather than assuming kale will germinate and establish equally well in every temperature.

Water and Feed for Steady Growth

Check the soil regularly and water deeply enough to reach the roots. Adjust to rainfall, temperature and soil type. Raised beds and containers may dry faster than in-ground plantings.

A light mulch around established plants can help conserve moisture and reduce weeds. Keep it from piling against the stems. Follow fertilizer directions and soil-test advice, avoiding concentrated fertilizer against young roots.

Kale may keep producing as weather warms, but leaf quality and growth can change. Heat, drought and the transition to flowering can make a planting less useful for tender leaves. Replace declining plants when the season and your garden plan call for it.

Watch for Pests Before Treating

Inspect leaf undersides and new growth for aphids, caterpillars and other pests. Identify the problem before choosing a response. Hand removal may be enough for a few caterpillars in a small planting.

Insect netting or an appropriate row cover can help exclude some pests when installed securely over a clean planting. Monitor heat beneath covers and avoid trapping existing pests inside.

Do not apply insecticidal soap simply as a routine preventive coating. It works by contacting susceptible pests and is not a lasting barrier against every insect. If treatment is needed, use a product labeled for kale and the identified pest, follow its directions and observe temperature precautions and harvest intervals.

Harvest Baby Leaves or Mature Greens

For baby kale, follow the variety's guidance for leaf size and cutting. If you want regrowth, avoid damaging the growing point and leave enough foliage for recovery.

For larger plants, pick the lower outer leaves while they are still in good condition. Leave the central growing point and enough healthy leaves to support continued growth. Avoid stripping a small plant bare.

Harvest regularly rather than waiting for every leaf to become oversized. Tenderness and flavor vary with variety, weather and leaf age, so try a few leaves at different stages to find your preference.

Bring Kale into the Kitchen

Wash harvested leaves under running water before preparation. Remove tough stems when appropriate, then use the leaves in sautés, soups, pasta dishes or smoothies. Young leaves can be used in salads, while larger leaves often benefit from cooking.

Refrigerate harvested kale promptly for short-term storage and use it while fresh. For freezing, follow reliable blanching and storage guidance rather than assuming raw leaves will keep their best quality indefinitely.

Whether kale becomes your favorite green or simply a reliable garden crop, cool-season timing and regular harvests help you get more from each planting.