Swiss chard growing in a vegetable bed
Updated: June 10, 2021

Planting Swiss chard facts

  • Hardiness: Semi-hardy (can withstand light frosts, but not heavy frosts or freezing; roots can tolerate colder temperatures than tops). Biennial (a plant that requires two growing seasons to complete its life-cycle) but treated as an annual. 
  • Planting: Direct seed into garden in early spring and late summer. Seeds can also be started indoors 5-6 weeks prior to transplanting into the garden. Be careful to minimize root disturbance. Tolerates partial shade (4-6 hours of direct light/day); grows best in 6-8 hours of direct sunlight.
  • Days to maturity: 50 - 70 (from direct garden sowing).
  • Spacing: Space seeds 2 inches apart in all directions, and cover with ½ inch of fine soil or 1inch of sandy soil. Thin plants to 4 inches apart when they are about 2 inches high. For larger plants, the spacing should be 8-12 inches.
  • Fertilizer needs: High requirement for nutrients, either from soil organic matter or fertilizers. Incorporate compost or fertilizer before planting. Side-dress as needed. Refer to Fertilizing Vegetables for details. 
  • Approximate yield: 8 to 12 pounds per 10-foot row.

Swiss chard problems

Bolting
Cercospora leaf spot
Leafminer
Root knot nematodes 

Root knot nematode damage on roots of Swiss chard
nodules on the roots of Swiss chard caused by root knot nematodes

The photos above of Swiss chard roots show the galls (swollen nodules) caused by root knot nematodes, Meloidogyne species. The location was a community garden in Baltimore. Interestingly, susceptible vegetable plants in adjacent beds were symptomless. This is a group of very common parasitic nematodes that live in the soil and feed inside plant roots. Typical symptoms include stunting, wilting, and loss of vigor.

Growing and care of Swiss chard

  • Swiss chard (Beta vulgaris var. cicla) is also known by the names silverbeet, perpetual spinach, spinach beet, crab Beet, seakale beet, and mangold. This leafy vegetable is a cultivated descendant of the sea beet, Beta vulgaris subsp. maritima. It is in the same species as beetroot (garden beet) except it lacks the swollen, edible storage root. The taproot is very large and woody on mature plants.
  • The word Swiss was used to distinguish chard from French spinach varieties by 19th-century seed catalog publishers. The first varieties of this popular leafy vegetable have been traced to Sicily.
  • Like beet seed, Swiss chard seed is actually a fruit or seed ball with several embryos. Unless you buy seed designated as monogerm seed — one embryo per fruit — you will need to thin the planting when plants are 2 inches in height.
  • Fresh, young chard can be used raw in salads. Mature chard leaves and stalks are typically sautéed. Their bitterness fades with cooking, leaving a refined flavor that is more delicate than that of cooked spinach.
  • Cultivars of chard include green forms, such as 'Lucullus' and 'Fordhook Giant,' as well as red-ribbed forms such as 'Ruby Chard,' 'Rainbow Chard,' and 'Rhubarb Chard.'  All parts of the chard plant contain oxalic acid.
  • Swiss chard leaves grow vigorously throughout the season.
  • Watering - Keep plants uniformly supplied with moisture for best performance. Water deeply and regularly during dry periods.
  • Weeding -Remove all young weed seedlings by hand and use a mulch laid along each side of the row to keep weed seeds from germinating. Thin by removing (cutting) plants in early summer so that spacing is about 8-12 inches apart.

Harvesting swiss chard

  • Harvest chard while the leaves are young and tender or after maturity when they are larger and have slightly tougher stems. 
  • Young leaves (smaller than 4 inches) may be eaten fresh in salads. 
  • Mature leaves may be chopped and sautéed. The “ribs” may be eaten like celery. 
  • It can be harvested until frost. 
  • At any point in the growing season, snip leaves 2 inches above crowns to rejuvenate plants. New, succulent leaves soon will be ready to harvest.

Storage and preservation  

  • Chard is extremely perishable. It stores best in very cold (32 degrees F), moist (95% relative humidity environment. Store in the refrigerator in a vented mesh or plastic bag.