Collard greens, a hardy member of the Brassica family, are cultivated for their large, nutrient-dense leaves. Proper spacing is a practical consideration for gardeners, directly influencing both the size of the harvest and the health of the plants. Maximizing the distance between plants allows the extensive leaf canopy to develop fully, leading to the large, tender leaves preferred for cooking. Adequate spacing also promotes air circulation around the foliage, preventing common fungal diseases like downy mildew and clubroot, especially in humid environments. The required distance varies depending on whether you start with seeds or transplants and the desired harvest size.
Spacing Requirements for Direct Seeding and Thinning
Direct seeding involves sowing seeds directly into the garden soil, requiring a subsequent thinning process to achieve the final plant spacing. Initially, collard seeds should be planted about \(1/2\) inch deep and spaced 1 to 2 inches apart along the row. This close initial spacing accounts for potential germination failure and allows the selection of the strongest seedlings later. Collards typically germinate within 6 to 12 days, and the first thinning must occur once the seedlings develop their first set of true leaves.
The initial thinning reduces crowding by removing weaker seedlings, leaving the remaining plants about 4 inches apart. This step gives the young plants enough room to establish a robust root system and grow larger leaves. The removed seedlings are often tender enough to be eaten as microgreens or young salad additions. The final spacing is achieved when the plants have grown larger, typically reaching 6 to 8 inches in height.
The second and final thinning establishes the permanent in-row spacing, which should be between 12 and 18 inches apart for full-sized plants. The precise distance chosen depends on the desired leaf size; spacing plants closer to 12 inches apart yields more plants with slightly smaller leaves. Conversely, spacing them 18 inches apart encourages the development of larger, more expansive leaves, ensuring each plant has the necessary space and light to reach its mature size.
Spacing Requirements for Transplants
When starting with transplants, the need for the multi-step thinning process is eliminated, as the plants are set at their final distance immediately. Transplants should be set into the garden bed at the same depth they were growing in their container, ensuring the root ball is fully covered. The final spacing for transplants follows the same parameters as the final thinning of direct-sown seeds.
For a continuous harvest of mature collard leaves, which involves picking the outer leaves over a long period, plants should be spaced 15 to 18 inches apart within the row. This wider spacing provides ample room for the large leaves to spread out without touching neighboring foliage. If the goal is to harvest smaller, semi-mature plants or “half-grown” rosettes for a single, earlier cutting, the plants can be placed closer together, generally 10 to 15 inches apart. Choosing the wider spacing of 18 inches promotes maximum air circulation, which reduces the risk of disease.
Row Distance and Wide Bed Layout
The distance between the rows of collards is important, as it facilitates maintenance and affects overall plant health. For traditional, single-row gardening systems, the space between rows should be 24 to 36 inches apart. This generous distance allows for easy access for weeding, fertilizing, and harvesting the large leaves without damaging the plants. The wide space also ensures that the mature leaves from adjacent rows do not overlap, which maintains the air circulation necessary to deter fungal issues.
In contrast to single-row planting, an intensive gardening approach often utilizes wide beds to maximize the use of space. In this layout, collards are planted in a grid pattern rather than a single line, essentially eliminating the concept of a row. This method involves spacing the plants 15 to 18 inches apart in all directions. Utilizing a multi-row bed system, where two to four rows are planted on centers of 38 to 60 inches, can provide greater yields and improved leaf quality by creating a dense canopy that shades out weeds. This grid layout maximizes the number of plants per square foot while still providing the necessary 15 to 18 inches of space between each plant for proper development.