How to Grow Swiss Chard
Swiss chard is a green with a unique taste. Swiss chard and beets are the same species, and they require a period of overwintering in order to set seeds. Plants can be lightly harvested in the first year for food, and then set to overwinter and produce seeds the following year.
Time of Planting
Plant seeds outdoors as soon as soil can be worked in the spring.
Direct sow seeds 2 inches apart and later thin to 6-12 inches apart. Sow seeds ½ inch deep.
Time to Germination
When growing for seed, increase spacing to 19 inches between plants in rows 36 inches apart, or to 24 inches on center. Staking plants is recommended.
Common Pests and Diseases
Downy mildew can be a problem for Swiss chard when grown close together as baby greens. Birds also enjoy the leaves, but protecting new seedlings under row covers can deter them.
When and How to Harvest
Swiss chard can be continually harvested throughout the season. Harvest the outer leaves at the base of the stalk, leaving four to five inner leaves to continue growing. Swiss chard can also be harvested in closer plantings as baby greens, cutting the leaves about 3 inches above the soil and returning every week or so. Allow plants to re-grow to 5-6 inches before harvesting again.
Swiss chard can be steamed or used in soups, or as an addition to salads and sandwiches.
Keep leaves in plastic bags in the crisper in the fridge for a few days.
How to Save Swiss Chard Seeds
This crop is a biennial, meaning that it will not set seed until the second year of growth. At seed maturity, plants of this species take up a fair amount of garden real estate. A benefit to growing Swiss chard for seed is that you can lightly harvest the plants in their first season for food, and then let them overwinter and harvest the seeds the next year.
Recommended Isolation Distance
Separate varieties by 800 feet to 1 mile.
Recommended Population Sizes
To ensure viable seeds, save seeds from at least 5 plants. When maintaining a variety over many generations, save seeds from 20-50 plants. If you’re saving seeds for genetic preservation of a rare variety, save seeds from 80 plants or more.
Assessing Seed Maturity
Seeds at the base of the flower stalks ripen first, and seed maturation continues up the stalks. Seeds change from green to a tannish-brown color as they mature.
Once seeds start ripening, there will almost always be a mixture of mature and immature seeds on plants. Harvesting when approximately two-thirds of the seeds are brown is recommended. Depending on the scale of seed collection, individual seedstalks can be cut or entire plants can be pulled from the garden and moved to a place where they can continue drying. Depending on the percentage of ripe seeds at harvest, 7 to 14 days should be a sufficient drying period.
Cleaning and Processing
The seedstalks can be threshed using one of several methods. Small lots and cut branches can be processed by running a gloved hand along the length of the stalk with a container placed underneath to catch dislodged seeds; stalks should be discarded once they are stripped of seeds. Larger lots and whole plants can be placed in large tubs or on tarps and treaded upon. Threshed seedstalks should be discarded, and the seed lot should then be screened and winnowed.
Storage and Viability
When stored under cool, dry conditions, beet seeds can be expected to remain viable for 5 years.