Swiss chard is a versatile and easy-to-grow leafy green, commonly cultivated as an annual for a continuous harvest of tender leaves and crunchy stalks. Successful cultivation begins with understanding the correct technique for placing the seeds in the soil. Proper initial planting density sets the stage for a healthy harvest by reducing competition and simplifying subsequent care steps.
Initial Sowing Density
Unlike many vegetables, a Swiss chard “seed” is actually a cluster, or dried fruit, that contains multiple embryos. This means a single cluster can produce anywhere from one to several individual seedlings.
For direct sowing into the garden, the standard practice is to plant two to three seed clusters per prepared spot. This slight over-seeding is a method of insurance, accounting for potential issues like poor germination rates or damage from pests. The seeds should be placed at a shallow depth of about half an inch (1.25 cm) and gently covered with fine soil. The area must be kept consistently moist to encourage successful germination, which typically occurs within seven to fourteen days.
Post-Germination Thinning
The multi-embryo nature of the seed cluster makes thinning necessary once the seedlings emerge. Thinning removes excess plants to ensure the remaining one has sufficient space, light, and nutrients to develop fully. If multiple seedlings grow in the same spot, they will compete, resulting in stunted and less productive mature plants.
The ideal time to thin is when young plants have developed their first set of true leaves, which appear after the initial cotyledons. At this stage, the seedlings are robust enough to handle the process. Instead of pulling out unwanted seedlings, which can disturb the fragile roots of the keeper plant, snip the weaker ones at the soil line using small scissors. The removed thinnings are perfectly edible and can be utilized as tender microgreens.
Final Spacing for Harvest Goals
The final distance between plants is determined by the gardener’s primary harvest goal. The recommended final spacing, from four to twelve inches, reflects the difference between harvesting young leaves and cultivating large, mature plants. This final spacing is achieved by continuing the thinning process.
Harvesting Baby Leaves
For gardeners focused on a continuous harvest of tender “baby leaves,” a closer spacing of four to six inches between plants is appropriate. This dense planting encourages a high yield of young foliage. The leaves can be repeatedly cut a few inches above the soil line for a “cut-and-come-again” style of harvest.
Cultivating Mature Plants
Conversely, if the goal is to produce large, full-sized stalks and mature leaves, the final spacing must be wider, eight to twelve inches apart. This generous spacing allows each plant to reach its full size, developing large, thick leaves and sturdy midribs.