If you’re planning your garden layout, a common question is how tall does kale grow. Understanding its maximum height potential helps you space plants correctly and avoid shading other crops. Kale is a versatile leafy green, but its size can vary a lot depending on the type you choose and how you grow it.
Generally, most kale varieties reach between 1 to 2 feet tall at maturity. However, under ideal conditions and with certain types, it can grow much taller, especially when it starts to flower. Let’s look at what influences kale’s height and how you can manage it for a great harvest.
How Tall Does Kale Grow
The simple answer is that kale typically grows 12 to 24 inches in height. But that’s just the leafy rosette. When kale bolts (sends up a flower stalk in its second year), the stalk can soar to 3, 4, or even 6 feet tall. This bolting stage is part of its natural lifecycle, but it usually makes the leaves more bitter.
Key Factors That Influence Kale Height
Several things determine whether your kale stays a compact bunch or becomes a giant.
* Variety: This is the biggest factor. Dwarf types like ‘Dwarf Blue Curled’ stay under a foot, while tall varieties like ‘Walking Stick’ kale are bred for their massive stalks.
* Growing Season: Kale grows as an annual for most gardeners, harvested in one season. If it overwinters, it will enter its second-year bolting phase and gain significant height.
* Sunlight: Plants grown in full sun (at least 6 hours) grow more robust and taller than those in shade.
* Soil Quality & Spacing: Rich, fertile soil with good compost supports larger growth. Proper spacing (usually 18-24 inches apart) gives each plant room to reach its full potential.
* Climate & Bolting: Heat stress can cause premature bolting, making the plant shoot up a stalk early in its first year.
Popular Kale Varieties and Their Typical Heights
Here’s a breakdown of common kale types so you know what to expect.
Compact Varieties (Under 18 inches):
* Dwarf Blue Curled: A classic, very hardy kale that grows 12-15 inches tall. Perfect for small gardens or containers.
* Lacinato/Dinosaur Kale: While its leaves grow long, the plant itself often stays a manageable 18-24 inches in a harvest year. Its height is more upright than spreading.
Medium to Tall Varieties (18 inches to 3 feet):
* Red Russian Kale: Tends to have a more open, spreading habit but the central stalk can reach 2-3 feet, especially if it overwinters.
* Winterbor Kale: A vigorous, curly kale that can form a sturdy central stem reaching 2-3 feet in height when mature.
Exceptionally Tall Varieties (Over 4 feet):
* Walking Stick Kale (Jersey Kale or Cow Kale): This is the champion for height potential. Grown primarily for its thick, dried stalk, it can easily reach 6-10 feet tall in its second year when flowering. The leaves are still edible when young.
How to Grow Kale for Optimal Size and Health
You want healthy, productive plants, whether they’re compact or tall. Follow these steps.
1. Start with Good Timing. For a harvest of tender leaves, plant kale so it matures in cool weather. Sow seeds directly (or start transplants) 4-6 weeks before your last spring frost or 6-8 weeks before your first fall frost.
2. Choose the Right Spot. Pick a location with full sun to partial shade. Ensure the soil drains well.
3. Prepare the Soil. Kale thrives in soil amended with plenty of compost. Aim for a soil pH between 6.0 and 7.0. A balanced organic fertilizer at planting gives them a good start.
4. Plant with Space. Sow seeds ¼ to ½ inch deep. When seedlings appear, thin them or space transplants 18 to 24 inches apart. Crowded plants will stay smaller and be more prone to disease.
5. Water and Feed Consistently. Keep the soil evenly moist. A layer of mulch helps retain water and keeps roots cool. Side-dress plants with compost or a balanced fertilizer every 6-8 weeks during the growing season.
6. Harvest Regularly. The best way to keep your kale at a manageable, leafy height is to harvest the outer leaves often. This encourages new growth from the center and delays bolting.
Managing and Controlling Kale Height
What if your kale starts getting too tall or bolts unexpectedly? Here’s what you can do.
* For Leaf Production: Regularly harvest lower leaves. If a central stalk begins to form prematurely (bolt), you can cut it off to encourage the plant to focus on leaf growth, though this is often a temporary fix.
* For Overwintered Plants: If you let your kale overwinter for an early spring harvest, it will inevitably bolt as temperatures warm. Enjoy the last of the leaves and the edible flower buds (they taste like broccoli rabe), then remove the plant.
* For Giant Varieties: If growing ‘Walking Stick’ kale, provide sturdy support for the tall stalk, especially in windy areas.
Common Problems That Affect Growth
Sometimes kale doesn’t grow as tall or healthy as expected. Watch for these issues.
* Pests: Cabbage worms, aphids, and flea beetles can stunt growth. Inspect leaves regularly and use row covers or organic pest control as needed.
* Diseases: Fungal diseases like black rot or powdery mildew weaken plants. Ensure good air circulation through proper spacing and avoid overhead watering.
* Nutrient Deficiencies: Pale or yellowing leaves can indicate a lack of nitrogen, which is crucial for leafy growth. Amend with a nitrogen-rich fertilizer like fish emulsion.
* Weather Stress: Extreme heat causes bolting. A sudden cold snap can shock young plants. Use shade cloth in intense heat and cover plants during unexpected frosts.
Frequently Asked Questions (FAQ)
How tall does curly kale grow?
Most curly kale varieties, like ‘Winterbor’ or ‘Dwarf Blue Curled,’ grow between 12 to 24 inches in height as a leafy plant. They can grow taller if they bolt.
What is the maximum height of kale plants?
The maximum height for kale is seen in the ‘Walking Stick’ variety during its flowering second year, where it can reach 6 to 10 feet tall. Most standard garden kale won’t exeed 3 feet unless bolting.
Does kale grow taller after cutting?
Harvesting leaves correctly doesn’t make the plant grow taller; it encourages it to grow bushier and produce more leaves from the center. Cutting off a bolting flower stalk may temporarily pause vertical growth.
Why is my kale so tall and skinny?
This is almost always a sign of bolting, usually triggered by warm temperatures or day length. The plant is putting its energy into making a flower stalk and seeds. The leaves may become bitter.
How much space does kale need to grow?
Space kale plants 18 to 24 inches apart. This gives them enough room to reach their full height and width, ensures good air flow, and reduces competition for nutrients.
Growing kale is rewarding, and knowing its height potential helps you make the most of your garden space. By choosing the right variety and providing consistent care, you’ll enjoy a plentiful harvest of this nutritious green. Remember, even if it gets taller than you expected, those flower stalks are a sign of nature doing its thing—and you can always save the seeds for next season.