Few vegetables give as much for as little as Swiss chard. A single sowing in spring keeps producing through the heat of summer and on into autumn, long after lettuce and spinach have bolted. The stems come in red, gold, pink and white, so the bed looks good as well as feeding you. Growing Swiss Chard is simple once you know how to space the plants and how to pick the leaves so they keep coming.
This guide covers chard from seed to the last autumn harvest. The advice comes from University of Maryland Extension, Utah State University Extension and University of Georgia Extension.
Why Growing Swiss Chard Is Worth It
Chard is a beet that has been bred for its leaves instead of its root. In fact, the seed looks just like beet seed, and the two plants are close relatives. If you already grow beets, Golden Beets: A Sweet and Less Earthy Root Variety covers the root-forming side of the family.
Chard earns its place for three reasons:
- It lasts. UMD notes that you can keep harvesting until frost, and the plants tolerate mild freezes.
- It handles heat. Spinach bolts as soon as summer arrives, but chard keeps growing through warm weather.
- It yields well. Both UMD and USU put the harvest at 8 to 12 pounds from a 10-foot row.
In the kitchen, the young leaves go into salads, while the larger ones are cooked like spinach. The thick stems can be chopped and sautéed separately, since they need a few more minutes.
Choosing Swiss Chard Varieties
Chard varieties differ mainly in stem colour. The white-stemmed types are usually the most vigorous, and the coloured ones the most ornamental.
UMD lists ‘Lucullus’ and ‘Fordhook Giant’ among the green-leaved, white-stemmed varieties, and ‘Ruby Chard’, ‘Rainbow Chard’ and ‘Rhubarb Chard’ among the red-ribbed ones. USU recommends ‘Rhubarb’, ‘Bright Lights’, ‘Lucullus’ and ‘Fordhook Giant’. UGA adds ‘Burgundy’ and ‘Winter King’, both ready in about 40 days. ‘Winter King’, as its name suggests, stands up well to cold.
‘Bright Lights’ is the classic mixed seed, with stems in half a dozen colours. It looks wonderful in a front bed, although it is slightly less hardy than ‘Fordhook Giant’.
When to Start Growing Swiss Chard
Chard is a cool-season crop that also tolerates warmth, so the planting window is wide. USU says you can plant seeds once the soil reaches 40°F. Germination is best between 55 and 75°F and takes 7 to 14 days. Above 80°F, however, fewer seeds come up.
In practice, sow in early spring, about 3 to 4 weeks before your last frost, as USU suggests. UGA puts it simply: sow as soon as the soil is workable. UMD recommends a second sowing in late summer for an autumn crop. For that one, USU advises planting early enough to mature before frost; First Frost Date: How to Find Yours and Protect Your Crops helps you count back.
Starting Chard Indoors
For an earlier harvest, you can start seedlings indoors. UGA suggests covering the seeds with ½ inch of potting soil and keeping them in a warm, bright place. Use a light medium; Seed Starting Mix: What to Buy, How to Make It and Why Garden Soil Fails explains what works. USU recommends setting transplants out near your last frost date.
Why Chard Seedlings Come Up in Clumps
Each chard “seed” is actually a small dried fruit that holds several seeds. As a result, two or three seedlings often appear from one spot. This is normal, and it is why thinning matters so much.
Planting and Spacing Swiss Chard
Sow the seeds ½ inch deep, as both UMD and USU advise. In sandy soil, UMD suggests going down to 1 inch.
Spacing depends on how you plan to harvest:
- Sow closely. UMD suggests seeds 2 inches apart, while UGA sows them 1 inch apart in rows 12 to 15 inches apart.
- Thin in stages. UMD recommends thinning to 4 inches when the seedlings are 2 inches tall. USU thins when the plants have 3 or 4 true leaves.
- Give full-size plants room. For large plants, UMD suggests 8 to 12 inches between them. USU uses 6 inches in the row, with rows 12 inches apart.
Do not waste the thinnings. They make excellent baby greens for salads, just like a Mesclun Mix Growing: Cultivating Salad Greens for Every Palate harvest.
Sun and Soil for Growing Swiss Chard
Chard does best in full sun. UGA calls for 8 to 10 hours a day, and UMD notes that 6 to 8 hours give the best growth. Still, UMD adds that chard tolerates as little as 4 to 6 hours of direct light. That makes it one of the better choices for a partly shaded bed; Shade Tolerant Vegetables: A Guide to Growing Without Full Sun lists others.
Chard likes fertile, well-drained soil rich in organic matter. UGA recommends loosening the soil to a depth of 10 inches and working in 3 to 4 inches of compost, pine bark or aged manure. Chard also grows well in large pots; Best Soil for Container Vegetables: Air Space Before Nutrients explains what to fill them with.
Feeding and Watering Chard
Chard is a leafy crop, so it needs a steady supply of nitrogen. UMD describes its nutrient requirement as high and recommends compost or fertilizer before planting, then side-dressing as needed.
The sources give practical amounts:
- Before planting. Without a soil test, UGA suggests 1½ pounds of 10-10-10 per 100 square feet.
- During the season. USU recommends ¼ cup of 21-0-0 per 10 feet of row, about four weeks after transplanting.
Water matters just as much. UGA advises about 1 inch a week, and USU gives 1 to 2 inches. UMD stresses that the plants should be kept uniformly supplied with moisture. Irregular watering makes the leaves tough and bitter, and in heat it can push the plants to flower.
Mulch helps a great deal. UGA suggests weed-free grass clippings, straw or wood chips to hold moisture and keep down weeds. For depths and timing, read Organic Garden Mulch: How Deep to Lay It and When to Wait.
How to Harvest Swiss Chard
Harvesting is where growing Swiss chard really pays off. You rarely pull the whole plant. Instead, you pick leaves from the outside and let the centre keep growing.
UGA says the first leaves are usually ready four to six weeks after planting. UMD gives 50 to 70 days for full-size plants.
Here is how to pick:
- Start with the outer leaves. UGA advises picking the largest outside leaves first, when they are about 12 inches long.
- Cut, do not tear. Use a knife or scissors near the base of the stem.
- Leave the heart. Keep the small leaves in the centre, so the plant can regrow.
- Pick young leaves for salads. UMD suggests eating leaves under 4 inches long raw.
If a plant gets tired and tough, UMD suggests cutting all the leaves back to 2 inches above the crown. The plant then sends up a fresh flush of tender leaves. The same idea works for many crops; Cut and Come Again Gardening: Which Crops Regrow and How to Cut Them explains which ones.
Growing Swiss Chard Through Summer and Frost
Chard is a biennial. It normally flowers in its second year, after a winter’s cold. However, UMD lists bolting among its problems, which usually happens when young plants go through a cold spell and then warm weather. UGA notes that you can keep harvesting until the plants bolt. For the signs and causes, read What is Bolting: How to Prevent Your Leafy Greens from Flowering Early.
In autumn, chard keeps going through light frosts. USU says it tolerates temperatures down to 32°F. A cover on cold nights extends the harvest further, and in mild areas the plants often survive winter and produce again in spring. Overwintering Spinach: Growing Greens in Cold Months covers the same techniques for its close cousin.
Pests and Diseases When Growing Swiss Chard
Chard is resistant to most plant diseases, UGA notes, but a few pests are worth watching.
Leafminers
Leafminers are the main problem. The larvae tunnel between the upper and lower surfaces of the leaf and leave pale, winding trails. UGA recommends covering the plants with cheesecloth or a row cover to keep the adult flies off. Floating Row Covers: Protecting Brassicas from Pests and Frost explains how to lay one. Remove and destroy damaged leaves as soon as you see them.
Other Pests
USU lists aphids, slugs and flea beetles. Flea beetles leave small holes in young leaves, while slugs chew larger ragged ones, especially in damp weather. Deer, UGA warns, also like chard, so fencing may be necessary in some areas.
Leaf Spot
UMD mentions Cercospora leaf spot, which causes small round spots with pale centres and dark edges. Good spacing, morning watering and removing infected leaves keep it in check.
Storing Fresh Chard
Chard is best eaten fresh. UMD recommends storing it at 32°F and high humidity, in a vented bag in the refrigerator. USU says it keeps for 1 to 2 weeks that way.
For longer storage, blanch and freeze it like spinach. Blanching Vegetables: Times, Steps and Why It Matters Before Freezing gives the steps. Since the stems take longer than the leaves, blanch them separately.
Make Growing Swiss Chard a Habit
A short row of chard feeds a family for months. Sow it in early spring, thin it well, keep it watered and pick from the outside, and it will produce from late spring until the first hard frost. So next spring, set aside a few feet of bed for growing Swiss chard, and add a second sowing in late summer for the autumn months.
Check out the author’s book here: The Year-Round Vegetable Garden for Beginners.
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