Among veteran gardeners, Swiss chard is well known as being easy to grow. Consequently, they tend to ignore it. On the other hand, beginners might assume that chard is as tricky as say, spinach, which can bolt easily in the heat. To both groups, I say look again.
Swiss chard (Beta vulgaris cicla), sometimes called stem chard because of its broad, flat stalks (as opposed to thin-stemmed leaf chard, also known as perpetual spinach), is a prolific cool-season vegetable that comes in a broad palette of colors and is packed with vitamins and minerals. It's the ideal vegetable for beginning gardeners. With good varieties, adequate soil fertility, and regular watering, you can harvest from late spring well into fall.
During more than 10 years of commercial growing experience, I've learned by trial and error the best ways to grow Swiss chard. Following are my tips for successful growing.
It seems that many gardeners, including veterans, don't pay much attention to which variety they grow. That's a mistake. Some varieties perform much better than others. Most Swiss chard varieties are categorized as white or red, but you will also find a range of colors, including yellow, magenta, and striped. This refers to the stem or leaf stalk color, not the leaves.
Probably the best Swiss chard in overall quality is white-stemmed 'Monstruoso', with broad, tender stalks. 'Large White Ribbed' is more productive but not quite as tender. Both are less likely than red-stemmed varieties to bolt (go to seed) after cold snaps and in dry weather. Their weak spot is pests. Insect pests such as leaf miners seem to prefer their large, smooth, succulent leaves to those of red kinds (which tend to have a stronger taste, closer to that of beet greens) or kinds with thick, savoyed (heavily crinkled) leaves.
White-stemmed 'Fordhook Giant' is the standard in our market garden. Its long, thick stems are topped by savoyed leaves, and it never bolts. Incidentally, another benefit of savoyed leaves is that insect damage, such as holes chewed by earwigs, is not as noticeable.
For most gardeners, red chard presents more of a challenge. Reds are more prone to bolting than white varieties are, especially after repeated exposure to temperatures in the low 50s followed by extended dry periods. As well, these varieties tend to have thinner stems and many stalks that emerge muddy red, and they are not as productive as white varieties.
Among the red varieties, the European 'Charlotte' resists bolting better than the standard 'Rhubarb'. It's also more productive and has broader stems that are more consistently colored. In general, red varieties aren't quite on a par with the better white varieties in characteristics such as yield and resistance to bolting, but they're certainly getting closer.
Other notable varieties are 'Bright Yellow', a new yellow-stemmed variety, and 'Bright Lights', a 1998 All-America Selections winner--the first Swiss chard ever to win the award. With 'Bright Lights', you can enjoy a milder flavor and all the vibrant chard colors, including oranges, pinks, and purples, without having to plant different varieties.
Chard is a forgiving plant. It won't fail if everything isn't just right. But for plants to thrive, they prefer the kind of soil most vegetables need: rich, slightly acidic (pH 6 to 7) loam. In gravelly or thin soil, mature stalks will be tough and stringy. If you're starting with poor soil, work in plenty of well-rotted compost before planting.
Sow seed outdoors a week or two before the last expected frost date in your area. Space seeds about 1 inch apart and 1/2 to 1 inch deep. As with beets, a Swiss chard seed is actually a dried fruit containing several seeds, so one seed can produce up to five seedlings. After germination, thin plants to one seedling every 4 inches, and thin again when they are about 6 inches tall to about 8 inches apart. Thinnings are delicious in salads or quickly sauteed.
Once plants are 6 to 8 inches tall, feed with a high-nitrogen organic fertilizer such as soybean, cottonseed, or alfalfa meal. Spread 10 pounds per 100 square feet, or about 1 pound per 10 feet of row, and cultivate it lightly into the soil. As an alternative fertilizer, use fish emulsion at rates recommended on the label. Apply fertilizer when soil is moist but not wet, and ideally just before rain or irrigation. Nitrogen is the key to producing good quantities of tender chard with luxuriant, dark green leaves. But don't overdo it. Too much nitrogen, and stems are less colorful.
My cool marine climate (USDA Hardiness Zone 6) is ideal for Swiss chard. Where summers are hotter and, more significantly, drier, plants may bolt prematurely. If you live where hot and dry summers are predictable, be sure to mulch plants by mid-June and irrigate often enough to keep soil evenly moist because it's not the heat that causes bolting, but water stress.
Swiss chard is relatively free of pests. Leaf miners are occasionally a problem. Prevent damage by covering young plants with a floating row cover in spring when leaf miner flies are most active. If these insects do damage plants, it affects only appearance, not yield.
Two fungal diseases sometimes occur. Cercospora leaf spot causes a large number of 1/2-inch, light tan to brown circular lesions with a distinct, dark brown to purplish halo. Fusarium wilt causes seedlings to wilt and shrivel and older plants to wilt and turn yellow. Neither of these is normally a serious problem. Rotating crops, improving drainage, and maintaining good moisture and fertility levels are usually enough to keep these diseases at bay.
Swiss chard requires only 45 to 55 days to mature, but you can harvest the baby leaves anytime. Either cut entire young plants just above the soil for salad greens, or cut off tender leaves once they reach the size you prefer. Use broader leaves in recipes that call for mature stalks, whole young leaves for salads.
Leaves left on too long will yellow and toughen, but these can be broken off and placed around the plant as mulch. To lengthen the harvest season, allow some plants to grow large in late summer. Thereafter, harvest from the center while preserving the growing point, and leave the large, older leaves to help protect the tender young leaves from frost. Remove any flower stalks to prolong the harvest. Swiss chard is actually a biennial and will flower after a period of exposure to the cold.
For the record, there's nothing particularly Swiss about Swiss chard. In fact, it's been grown in Europe since classical antiquity. Ancient Greeks and Romans used chard leaves as a wrapping for baked eel. But how do modern Swiss cooks prepare it? They stuff mature chard leaves with a meat or vegetable filling and bake it in a creamy sauce to make capuns. Alpine villagers combine chard stalks with buckwheat noodles, potatoes, green beans, and Gruyere cheese to create pizzoccheri, a hearty gratin.
However you prepare Swiss chard, the leaves are an excellent substitute for spinach during the hot months, and the stems may be used like asparagus. Baby chard can be cooked whole, but the stalks and leaves are usually cooked separately. Lengthy cooking dulls the colors, so light cooking is preferable, particularly for brightly colored varieties. Swiss chard is an excellent source of vitamins A and C and a good source of iron and fiber.
Syndey Penner gardens and writes in Berwick, Nova Scotia.