A Gardener’s Field Manual
Kale is a cold-weather crop that doesn’t fare well in warm environments. Cool weather helps provide kale with rich, bushy leaves that leave the plant green and flavorful. Kale needs a good amount of sun through the day for optimal growth.
Type of Plant
Lots of sunlight
Soil Type & pH
Loamy soil, neutral or mildly alkaline pH
4, 5, 6, 7, 8, 9, 10, 11
Quick Tip: You can grow kale in temperatures as low as 20 degrees Fahrenheit; in fact, if you grow it in colder weather, it tends to taste sweeter.
If you’re growing kale indoors, find a sunny location in your home or use LED lamps. Keep kale’s soil moistened, but not wet. Plant kale near potatoes, celery, onions, cucumbers, or beets. Plant rosemary, sage, or catnip near kale to keep pests away. For more information about growing kale, check out our detailed resources in the right sidebar.
Kale is a vegetable that doesn’t absolutely require a lot of full sun, but too much shade will hinder its growth, or keep it from growing altogether. For the bushiest, fullest kale production, you’ll want plenty of sun through the day.
If your kale is in a spot in your garden with partial shade, don’t worry. It will still grow, but may not be as leafy or green. For ideal lighting, make sure your kale has at least 6 hours of sun per day.
If you’re growing kale indoors, you may find that getting enough sunlight for your kale is a problem. If you don’t have an area of your home with plenty of natural sun during the day, your kale may not thrive like it could if it were outside in the sunlight.
In this case, it’s best to use a LED grow lamp. Keep other plants away from your kale’s light, as they could shade light from the short and stocky plants. Also, use the same-size pots for your kale to ensure that your plants are the same height and, therefore, won’t compete with each other for the light source.
Soil for kale should be well-draining and moist. Your garden bed for kale should have a pH of between 6.5 to 6.8, which will keep it at an adequate level for nutrient intake and discourage disease, like clubroot. An organic fertilizer mixed into the garden bed evenly can promote healthy kale growth. If your soil needs some extra care, mix in the fertilizer well and allow it to work its magic for a week or so before planting kale.
You can plant kale in rows about two feet apart from each other, or simply space seedlings about 18 inches apart. The plants grow bushy and can spread a couple of feet wide, so you’ll want adequate space to keep them from competing with each other for nutrients and sunlight.
You may choose to mulch kale before warm weather hits, so its roots are protected from the warmth. This will help its moist soil stay cool to lessen the risk of harboring bacteria that can cause disease.
Although kale can survive in drought conditions for a short time, the quality of its leaves, and its taste, will suffer. The key to long-lasting, healthy, and great-tasting kale is to keep its soil evenly moist, rather than dry or wet.
One of the best ways to ensure that water remains even in kale’s soil is by mulching your kale’s garden bed. Not only does mulching help the soil retain water, but it also keeps it at the proper temperature for less risk of overheating and disease. Grass clippings, shredded newspaper, and compost all work well for mulch.
If you choose not to mulch, check your kale’s soil every few days. Dig a small hole near your plants with your fingers. If the soil is dry a couple of inches down, it’s time to add some water. In areas with adequate rainfall, you shouldn’t need to water much. In drier areas, water with your garden hose or a sprinkler until the soil is moist.
You should try to water kale in the morning so it can dry throughout the day. If water remains on the bushy leaves for too long, they can become scorched by the sun or rot.
Kale does not fare well in warm weather, which causes it to quickly lose its quality and flavor. Warmth can cause wilted leaves, disease, and a bitter flavor. Therefore, you should check your hardiness zone for the best time to plant kale in your area. If you experience heat through most of the year, it may be best to grow kale indoors in a room where you can control the cooler temperatures.
Kale can grow in most hardiness zones, but you’ll need to plant kale according to the weather in your region. Kale takes about 70 to 80 days to grow from seed, so you’ll need to give your kale several weeks for seeds to germinate in warmer weather so established plants can thrive in cooler weather.
For regions with cool summers, plant in the early spring for a fall harvest. In hot summer regions, you’ll want to plant kale closer toward the end of summer to harvest later in the fall or early winter. For areas with mild winters, plant kale seeds in the fall to harvest in winter.
WHERE TO GROW
Kale can be grown in your outdoor garden or indoors in containers. Since kale is finicky about temperatures, it can be difficult to grow indoors, unless you have a room in your home that you can keep cooler than others. Kale does not typically grow well in a greenhouse because of its need for cooler temperatures.
It can be helpful to grow kale in easily moveable containers in your home so you can transport them outside for cooler air during the day. If you do not have a room with adequate sunlight to give your kale for several hours per day, you can also move the containers to a sunny porch, or outside in the garden, to soak up the sun.
Here’s a helpful video about planting kale indoors, if you choose to grow it year-round in containers:
Kale grows well alongside other plants that can give it a small amount of shade through the day, but not take away too much sunlight. You should also take care to space other plants a couple of feet away from kale so they don’t hinder your kale’s growth or compete with its nutrients.
Some vegetation that helps kale thrive are onions, potatoes, celery, cucumbers, beets, spinach, and swiss chard. You can also try potent-smelling plants, like rosemary, catnip, sage, and garlic, which can help deter pests from bothering your kale plants. Dill can improve the growth and health of your kale plants.
Avoid planting tomatoes near kale, as tomatoes tend to compete with produce in the cabbage family for nutrients, sunlight, and water.
For more information on growing your own kale, take a look at our right sidebar. Here, you’ll find detailed resources for everything you need to know about growing kale in your garden, indoors, or in containers. Before you get too far, read our articles to learn about the varieties of kale, best fertilizers for optimal growth, pest control, and growing requirements so you can grow gorgeous, delicious kale at home.
Did you know?
Between 2007 and 2011 the number of countries that produce kale grew from 78 countries to 202.
want to dig deeper?
Kale fact source: Bloomberg.