How to Grow Kale | The Complete Guide to Growing Kale + 5 Harvest Tips

Kale in garden

Kale is the hardy, cool-season green that’s perfect for growing as the temperature drops. Part of the cabbage family, kale is arguably the most nutrient-dense food in the world and it’s shockingly easy to grow. So how to grow kale?

Here is your complete guide to growing kale — from planting, to care, to harvesting. We cover how to avoid pests, exact garden soil needs, and more.

WHEN TO GROW

Kale is one of those rare vegetables that can be planted both in early spring and early fall. In fact, in some cases, it’s even a year-round plant. If the weather in your climate doesn’t drop below 20° F, a kale garden is an option any time of the year.

To create a spring kale vegetable garden, plant in early spring before the summer heat becomes too much for the plant — best 3-5 weeks before the last frost. For a fall garden, plant approximately 6-8 weeks before the first frost.

This being said, kale seeds germinate most successfully in soil that is about 45°F, so plant according to your climate!

It may sound odd, but kale actually grows best in the cold air temperatures of fall. Kale is frost tolerant, meaning it can continue to grow successfully after a light frost. In fact, kale tastes better when grown in the fall; the cold weather brings out the natural nutty flavor of the leaves and produces a more tender harvest.

LOCATION

Essentially, kale can be grown everywhere — even the tropics will work with a little bit of shade! The city is no exception. You definitely don’t need a backyard to grow kale; this leafy green is a perfect candidate for a container garden. Be sure that your continue is at minimum 12 inches in diameter and deep enough to support kale’s root system.

Soil is a major part, if not the most important part, of your garden’s home. Be sure to use soil with good drainage. Enrich the soil with compost and fertilizer before you set out your seeds/seedlings, refreshing occasionally.

The ideal soil pH for a kale garden is between 6.5 – 6.8. This most successfully prevents clubroot disease. If clubroot disease isn’t a problem in your garden, you can push it as low as 6.2 pH. Test the soil with a do-it-yourself kit or use a complete Gardenuity kit, which comes with kale seeds/seedlings and soil specifically curated for optimal growth.

PLANTING

Direct sow vegetable seeds 1/4 inch to 1/2 inch deep into well-drained soil. Water deeply after planting. After two weeks of growing, thin the seedlings, spacing them about 8-12 inches apart

Growing from transplants, or ‘adolescent’ aged plants, is a great option for fall growing. Doing so avoids the tenuous beginning growing stages and increases your chance of a successful harvest — especially if your fall garden is off to a late start or it’s a bit chillier than expected.

You can either begin your seeds indoors and transfer or buy your transplants from a farm partner you trust. After planting seedlings, allow at least 2 weeks for the seedlings to adjust to their new home. Consider replanting as a minor trauma for your plant. Watch them carefully during this period, being sure to water them regularly.

Because the soil gets cold and acts as a mini-fridge, a kale harvest can last much longer than normal. Use successive planting to extend your harvest throughout the winter. To do so, plant additional kale plants every 2-3 weeks until the first frost or until you run out of space.

Pro tip: Beets, celery, cucumber, herbs, and spinach made good neighbors for kale, while strawberries and tomatoes are unfriendly to kale’s growth.

WATER

Water your kale garden regularly, being careful not to overwater. Generally, kale prefers a nice even supply of water — about 1 to 1.5 inches per week.

Use the thumb test as a foolproof water to determine if your plants need water. Stick your thumb about an inch deep into the soil. If the soil is moist, wait another day. If it’s dry, water immediately.

SUNLIGHT

Kale grows best in full sun, but will tolerate partial shade. If your kale receives fewer than 6 hours of sun daily, your plants will be thinner and produce fewer leaves, but they’ll still be edible and delicious.

PESTS

Luckily, pest populations tend to drop dramatically in the fall. Regardless, watch out for the following pests.

Cabbageworm

Cabbageworm is the larvae of cabbage white butterflies. These pests are velvety green worms that are fond of chewing holes in kale leaves. Remove infested leaves.

Aphids

Gray–green cabbage aphids are often found in clusters in the folds of frilly kale. To treat, spray with organic insecticidal soap. If a specific leaf is badly infested, pick the leaf off the plant and discard.

Harlequin Bugs

Harlequin bugs are colorful black and orange pests that plague older kale plants. The best way to protect seedlings from these (and other pests) is to cover them with row cover or another lightweight fabric.

HARVEST

Direct sowed kale plants typically mature in 55 – 75 days, while transplants are ready to harvest in about 30 – 40 days. You’ll know that your kale is ready to harvest when the green leaves are about the size of your hand. Kale will grow until it’s 20° F. As such, if you protect your kale with a row cover, you may be able to harvest all winter long.

Here are 5 kale harvesting tips to make your harvest easier.

You can harvest fully mature leaves 55-75 days after sowing, baby greens 20-30 days after sowing, or microgreens 12-20 days after sowing.
Microgreens and baby leaves are particularly tender and can be eaten uncooked — use them in salads! Larger leaves should be cut and cooked like spinach, removing the tough ribs before preparing.
Pick about one fistful of leaves per harvest. To lengthen your harvest, avoid picking the terminal bud, which is found at the top center of the plant.
Pick the oldest leaves first which are usually found at the lowest section of plants. Work your way up the stalk as the growing season continues.
As you harvest, discard leaves that appear yellow or ragged to keep your plants healthy.

Overwintered plants will eventually bolt. You’ll know your kale plants have bolted because they will start to produce yellow flowers. Once this happens, it’s time to tear up your kale garden and replant with something new.

STORAGE

Kale does not keep well, as it loses flavor quickly. We suggest you only harvest what you can use in a day. Return to your plant for more fresh eats as needed!

Store as you would any other leafy green. We suggest doing so in a plastic bag lined with dampened paper towels. For freshest tasting results, wait to wash leaves until right before serving. Alternatively, dry or freeze your kale harvest.

If your kale leaves get too big and therefore tough, don’t waste the leaves! Massage them instead. When you massage your kale, you break down the fibrous tissue to create a more tender edible green.

To do so, remove the ribs and woody pieces from the end of each leaf. Tear into bite-sized chunks and put in a bowl. Add olive oil until lightly covered and a pinch of salt.

Begin mixing and working this into the leaves like you’re kneading bread dough. After 5 minutes, the leaves should look darker in color and feel more supple. Serve immediately!