Kale is a hardy, cool-weather crop valued for its nutrient-dense leaves. Establishing the correct space for each plant is fundamental to a successful harvest. Sufficient room prevents crowding, ensuring proper air circulation to minimize fungal diseases. Adequate spacing also ensures plants access necessary water and soil nutrients, leading to larger, healthier leaves and a better yield.
Standard Spacing Requirements for Garden Beds
For most common varieties of kale grown in traditional in-ground rows or raised garden beds, the standard recommendation for mature plants is to space them 12 to 18 inches apart. This allows the plant’s central stalk to develop fully and gives the large leaves room to spread without overlapping. If planting in long rows, leave 18 to 24 inches between the rows themselves to provide walking space and ensure good light penetration.
The intended harvesting style directly influences how close plants can be situated. For a “full harvest,” where the plant reaches maximum mature size, use the wider 18-inch spacing. For the “cut-and-come-again” method, where only small, tender outer leaves are harvested regularly, a tighter spacing of 8 to 12 inches is acceptable.
When starting from seed, sow closely and then thin seedlings to the final desired spacing once they develop their first set of true leaves. Thinning ensures only the most vigorous plants remain to utilize resources.
How Kale Variety Affects Necessary Space
The mature size of a kale cultivar determines the necessary space. Large, open-pollinated varieties, such as ‘Red Russian’ or Lacinato types, can spread 24 inches or more at full maturity. For these vigorous growers, providing 18-to-24-inch spacing is necessary to prevent overcrowding and stunting.
Conversely, compact or “dwarf” varieties, such as ‘Dwarf Blue Curled Scotch,’ are bred for smaller footprints. These cultivars may only reach 12 to 14 inches in height and can tolerate closer spacing, sometimes as tight as 10 to 12 inches. Always consult the specific mature size and spacing recommendations printed on the seed packet before planting.
Room Needed for Container Growing
Growing kale in containers requires focusing on soil volume and depth rather than lateral garden space. A single mature kale plant needs a container large enough to support its root system and retain moisture. The minimum recommended size is a pot with a capacity of 3 to 5 gallons, translating to a container at least 10 to 12 inches wide and equally deep.
Although kale only needs about 8 inches of soil depth, the wider and deeper container provides stability and buffers against rapid moisture loss. If using a large trough, multiple plants can be grown as long as 12-inch spacing is maintained between each plant. Adequate drainage holes are required to prevent waterlogged soil conditions that lead to root rot.
Techniques for Maximizing Limited Space
When garden space is limited, specific planting strategies can increase the yield per square foot.
Square Foot Gardening (SFG)
The SFG principle dictates a precise layout. For full-size mature kale, SFG typically allocates one plant per square foot, providing 12 inches of space in all directions. If the goal is to harvest baby kale leaves, density can be increased to four or even nine plants per square foot, as they are harvested before reaching full mature size.
Succession Planting and Vertical Gardening
Succession planting involves staggering small plantings every few weeks. This avoids planting the entire crop at once, reducing the immediate space needed and ensuring a continuous supply of fresh leaves. Vertical gardening setups, such as tiered planters or wall pockets, utilize vertical space that might otherwise go unused.