Whether you garden in the ground, in raised beds, on the patio, or anywhere else, kale is a great addition or re-addition to your plant family. Read on for simple, straightforward specifics about growing kale.
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Family | Container Size | Good Companions | Bad Companions | Soil Conditions | Germination | Sun | Water | Temperature Range | Height | Lifespan | Reproduction | Yield Per Plant | Ingestibility | Further Reading
What Family Does Kale Belong To?
Kale (Brassica oleracea var. sabellica) belongs to the Brassicaceae family, also known as the cabbage family.
Some of its relatives include cauliflower, radishes, and broccoli.
What Size Container Should I Use for Growing Kale?
The minimum container depth recommended for kale is 8 inches.
However, a container that is at least 12 inches deep is preferred. This size is less likely to cramp the roots, so it can result in larger leaves.
A container that is at least 12 inches deep is especially recommended if you are growing other plants in the same container as your kale such as the companion plants listed in the next section.
Read more about this in our Choosing the Right Planter for Your Container Garden article here.
What Are Good Companion Plants for Kale?
Some of kale's best companions are as follows:
- Beet
- Celery
- Cucumber
- Lettuce
- Artichoke
- Onion
- Peas
- Potato
- Radish
- Spinach
- Orach
- Garlic
- Basil
- Dill
- Chamomile
- Mints like peppermint and spearmint
- Rosemary
- Sage
- Thyme
- Marigold
- Nasturtium
- Purslane
- Cilantro
- Lovage
- Lemongrass
- Leek
- Catnip
- Catmint
- Buckwheat
- Chives
- Chard
What Are Bad Companion Plants for Kale?
Kale is not compatible with every plant. Some things to avoid planting with kale are as follows:
- Strawberry
- Sunflower
- Fennel
- Black walnut
- Other closely-related Brassicas such as broccoli and cauliflower, which compete for the same nutrients and attract the same pests
What Soil Conditions Does Kale Need?
Kale prefers loamy, well-draining, fertile soil. It especially prefers soil that is rich in nitrogen.
How Long Does Kale Take to Germinate?
Kale takes 5-8 days to germinate at a temperature of 40-85°F.
How Much Sun Does Kale Need?
Kale can grow in full sun to part shade.
In other words, it grows fastest in full sun. It will still grow in dappled shade or part shade, just at a slower rate.
My personal experience has been that kale grows much slower in the shade than in full sun, especially compared to other leafy greens, but it does grow. If you are not in a hurry for your kale, it can be a solid shade vegetable.
Keep in mind that kale grown in the shade will be more susceptible to pests and disease since it takes longer to grow.
Sun recommendations can vary by region, and kale grown in hot areas or in warmer conditions than the ideal temperature range noted below may need more shade.
How Much Water Does Kale Need?
Kale needs 1 to 1.5 inches of water per week.
What Is the Ideal Temperature Range for Growing Kale?
Kale grows fastest in temperatures of 65-75°F.
This is its ideal temperature range. Although it will grow in temperatures both cooler and warmer than this range, the growth could be slower or even stunted.
Minimum and maximum temperatures will vary by variety. Some kale varieties are bred for late fall to early winter harvests and others for warmer climates.
Kale is one of the hardiest vegetables. Hardiness varies greatly by variety, but Red Ursa and other hardy kales can survive at temperatures down to -10°F.
Most kales pause their growth in the winter, but the fact that they can survive winter makes them an excellent biennial choice for colder regions. You may choose to overplant kale that matures in the fall so that you can continue to harvest its leaves throughout the winter.
How Tall Does Kale Get?
The average height of kale is 1-2 feet.
The average width of kale is also 1-2 feet.
Is Kale Annual, Biennial, or Perennial?
The vast majority of kales are biennial, meaning that their life cycle spans 2 years, and they flower, produce seed, and die in their second year.
Kale produces its flowering stalk and seeds earlier in its second year than most biennial plants do. These are typically produced in the spring. Once the seed stalk has flowered, kale leaves become bitter and less pleasant to eat.
Sea kale, Kosmic Kale, and a small number of new varieties are perennial, meaning that they live longer than a couple years. Most of these are technically not the same subspecies as kale but resemble it closely.
For example, sea kale (Crambe maritima) is not a true kale, but it is a close relative that is very similar to kale in both appearance and taste.
How Does Kale Reproduce?
Kale reproduces by seed.
It sends up a flowering stalk in its second year, usually in the spring. This stalk then produces seeds.
How Much Kale is Produced Per Plant?
For kale, how much is produced per plant (also called the yield) depends on the variety, climate, and growing conditions.
Kale grows and regrows leaves continually throughout its lifetime until it goes to seed. Each plant yields a total of 100-400 leaves when grown in optimal conditions.
Can Kale Be Ingested?
Kale leaves are edible.
Although kale is highly nutritious, it does not have any known uses in herbal preparations.
There are no known safety concerns associated with ingesting kale leaves.
Further Reading
This article is intended as a quick-reference guide for gardeners. Consult your seed packet or seed catalog for variety-specific information.
When you have a bumper crop of kale rolling in, you may not have enough time for long, complicated recipes or many-step preservation procedures. Check out my article on quick, simple uses for kale here!
Kale is featured in these Plant to Plate articles:
- Simple Uses for Kale
- Choosing the Right Planter for Your Container Garden
- Gardening in Full Sun
- Gardening in Dappled Shade
- Gardening in Part Shade
- How Temperature Affects Plant Health