Kale is a popular cool-season vegetable. Understanding the visual characteristics of kale seeds is important for proper identification, especially for gardeners who save or purchase them for planting. Knowing what a kale seed looks like helps ensure the successful cultivation of the desired variety. This visual knowledge is also helpful when distinguishing kale seeds from those of its many close relatives in the garden.
Physical Characteristics of Kale Seeds
Kale seeds are small, dark, and nearly spherical objects, consistent with their placement in the Brassica genus. They generally measure between one and three millimeters in diameter. Their tiny size can make handling them challenging during planting.
Mature kale seeds are typically deep reddish-brown, dark brown, or nearly black, though color can vary slightly by cultivar. The shape is usually spherical, though minor irregularities may result in a slightly ovoid appearance. Under magnification, the seed coat texture is not smooth but possesses a finely pitted or slightly rough surface.
The seed develops inside a silique, which is a long, thin seed pod. This pod turns brown when the seeds inside have reached maturity and are ready for harvest. The collective appearance of these small, dark, pitted spheres confirms their identity as a member of the cabbage family.
Identifying Kale Seeds vs. Other Brassicas
Distinguishing kale seeds from those of other Brassica species, such as cabbage, broccoli, or collards, presents a significant challenge because they share a nearly identical appearance. These vegetables are cultivars of Brassica oleracea or closely related species, meaning their seeds are the same size, color, and shape. The general description of a small, dark, round seed applies to nearly all garden brassicas, which often leads to confusion for seed savers.
To accurately differentiate between them, high magnification (30 to 40 times the original size) is needed to examine subtle variations in the seed coat texture. Experienced botanists look for minute differences in the pattern of ridges and shallow interspaces on the seed surface to confirm the species. Kale seeds maintain a uniform appearance across different cultivars, despite the wide variety of leaf shapes and colors in the mature plants.
Proper Storage for Seed Viability
Once kale seeds are identified and cleaned, proper storage is necessary to maintain viability for future seasons. Seeds must be completely dry before storage to prevent the development of mold or decay. The two most important factors for long-term viability are consistently cool temperatures and low humidity.
An ideal storage environment is a cool, dark location, such as a refrigerator, where the temperature is maintained around 50°F and the relative humidity is kept low, near 40 percent. Seeds should be stored in an airtight container, like a sealed glass jar, or in paper envelopes placed inside a secure container. It is important to clearly label the container with the specific variety and the date the seeds were harvested or stored.