Kale, a member of the Brassica family, is a resilient and popular garden crop that thrives in cooler temperatures. Achieving a successful harvest requires a precise and careful planting technique, especially when sowing seeds directly into the soil. Understanding the correct procedure for seed placement, depth, and eventual spacing ensures maximum germination rates and a higher yield of healthy, leafy greens. The initial stages of planting are foundational for the plant’s life cycle.
Determining the Ideal Number of Seeds
The general recommendation is to plant two or three kale seeds in each designated planting spot, which acts as insurance against unpredictable germination. Kale seeds do not have a 100% germination rate due to factors like seed age, soil conditions, and slight variations in the microenvironment. Planting multiple seeds increases the probability that at least one viable seedling will emerge, preventing wasted space.
This practice also allows for a crucial selection process once the seedlings have sprouted. Gardeners can choose the single, most vigorous plant to keep. For home gardeners starting seeds indoors, planting two seeds per cell guarantees a plant in almost every spot and allows for selection before transplanting.
Thinning Seedlings for Optimal Yield
The necessity of planting multiple seeds leads directly to thinning the seedlings to a single plant. If multiple kale seedlings are left to grow in the same spot, competition for light, water, and soil nutrients will cause them all to remain small and underdeveloped. This process must be performed once the seedlings have developed their first set of true leaves. These are the second pair of leaves that emerge, resembling the mature kale leaf shape and distinguishing them from the initial, round cotyledons.
The appropriate technique for thinning is to use a small pair of scissors or sharp snips to cut the unwanted seedlings at the soil line, leaving the strongest plant undisturbed. It is generally advised to cut rather than pull the excess seedlings because pulling can inadvertently damage the delicate root system of the keeper plant. This directs all available resources toward the single remaining plant, allowing it to grow to its full size.
Proper Depth and Spacing Requirements
The physical context of the planting “hole” is just as important as the number of seeds placed within it for successful kale growth. Kale seeds are small and require shallow planting, typically between 1/4 to 1/2 inch deep in the soil. Planting them too deeply prevents the emerging seedling from reaching the surface, while planting too shallowly risks the seeds drying out before germination.
The final spacing between mature kale plants is a major consideration, as they require significant room for large leaf development and adequate air circulation to prevent disease. Once the seedlings have been thinned, the remaining plants should be spaced approximately 12 to 18 inches apart, depending on the specific variety. Immediately after sowing the seeds and lightly covering them with soil, a gentle watering is necessary to settle the soil and initiate the germination process.