I will be the first to admit that Swiss chard is not my favourite green in the world.
GASP! I know! To be honest, I find it a little bitter for my taste.
So, why am I writing an article on how to grow Swiss chard, even though I don’t particularly like it?
Well, despite my views on Swiss chard, and since this is our first year as market farmers, we want to test it out on our customer demographic because it can provide fresh, succulent greens throughout the summer with very little effort and very few troubles.
Not to mention, there are some colourful varieties that look amazing on display at the farmer’s market.
In this article, we will be learning from our resident expert, Pam Dawling, author of Sustainable Market Farming for her expertise on all things Swiss chard.
Varieties of Swiss Chard
Swiss chard is available in several shades of green, a mix of rainbow shades, and various selections of single colours.
The white stemmed, green-leafed varieties are more productive, as they have more chlorophyll than the coloured leaf kinds. They are also less likely to bolt under stress.
Fordhook Giant, the most easily found variety, is the workhorse. It has thick crinkled leaves and is very bolt resistant.
Lucullus has a more tender leaf and is a lighter shade of green.
Monstruoso has very broad stalks.
Large White Ribbed is more productive but not quite as tender.
Red kinds seem to have a stronger flavour, closer to beet greens, they are less troubled by leaf miners as well.
Red varieties are more likely to bolt if subjected to prolonged periods below 50°F (10°C) followed by extended dry conditions.
Charlotte resists bolting better than Rhubarb/Ruby Red and is more productive, with broader stems.
Bright Lights and Rainbow are two varieties of multicolored chard. Bright Lights has thinner stems and brighter colours than Rainbow.
Although it can be sown earlier and used as a spring crop, chard really comes into its own if sown later in spring, to mature as spinach finishes up. It only takes about 50 days from sowing to maturity.
Chard needs a soil rich in organic matter, with a pH over 6, if it is to crank out large quantities of healthy leaves.
It is an easy crop that will grow in partial shade or full sun and in all soil types. It does need regular watering throughout the season, however, as water stress can cause bolting if the weather has been cool.
If yield drops consider supplementing with compost/soybean meal/cottonseed meal or alfalfa meal, or foliar feed with kelp or fish emulsion.
Nitrogen is the vital ingredient for growing luxuriant tender chard. Be careful, as always, not to apply too much or the colours of the stem will fade.
Chard plants continue producing leaves into the winter, so for cooking greens, there is no need to sow succession crops.
Sowing Swiss Chard
If you want to grow chard in spring, you can direct seed two or three weeks before the last frost or start flats earlier.
If you prefer spinach or kale in the spring and switch to chard for summer, sow in plug flats or soil blocks 3 weeks before your last frost date.
Using transplants can enable you to get an earlier crop from the future chard bed, or finish growing a good winter cover crop before you put the bed into production.
Each seed is actually a dried fruit containing several seeds, just like a beet seed, so you’ll likely get several seedlings in each cell.
When the seedlings have a leaf or two, thin them to 1 per cell by snipping off the extras.
The temperature range for germination is 41 to 95°F (5 to 35°C), with optimum germination temperature of 59 to 77°F (15 to 25°C).
Germination time is 4-20 days.
For direct seeding, sow about 6 seeds per foot (5 cm apart), 1/2 inch (1 cm) deep, in rows 12 to 24” (30-60cm) apart.
As they grow, the plants can be thinned gradually until 12” (30 cm) apart. Sowing at closer spacing provides smaller leaves and is better for salads. The thinnings are an excellent salad crop.
Pam plants her chard at about 3 to 4 weeks of age. She transplants into beds already mulched with rolled oat bales of spoiled hay, making ‘nests’ through the hay down to soil level at 12” spacing.
The plants will grow large, so she puts only two rows in a 4-foot bed with 1-foot paths. The mulch controls weeds and keeps the soil cooler and damper through the summer.
Pests and Diseases
Swiss chard generally has few pests and diseases.
One disease Pam has had some trouble with is Cercospora, a fungus that grows as small round tan or brown spots on the leaves.
Look for a purplish halo, or take a hand lens and look for black fruiting spores in the centre of the spots. Remove the affected leaves to a hot compost pile and hope for the best.
Fusarium wilt can cause seedlings to wilt and shrivel, or older plants to wilt and turn yellow.
Slugs can be a bother in cool climates, but less so in summer.
Root-knot nematodes have caused trouble in Florida; crop rotation helps avoid them.
Flea beetles have been reported on chard in Pennsylvania.
Leaf miners may be seen in northern areas.
Use row covers in spring when the miner flies are most active, or against flea beetles.
Blister beetles have also been known to cause problems in the South.
Adult beetles emerge from the soil in areas where an infestation occurred the previous year. Their preferred crops are tomatoes, potatoes, and eggplant, with beets and chard as their second choice.
If the numbers justify an action, handpick with gloves on, or brush into a scoop improvised from a plastic bottle. Drop the beetles into soapy water.
If numbers of blister beetles are low, live with them and know that their larvae eat grasshopper eggs, and will save you from a pesky grasshopper plague later in summer.
Swiss chard will reach maturity 50 to 60 days from sowing.
Chard is picked as individual leaves and sold as bunches.
Pick outer leaves (discarding the damaged or tough ones) and stand them in tall buckets, adding an inch of cold water to help prevent the leaves from wilting.
Pull the stems outward and twist low down (or cut with a knife), to avoid leaving stubs, which will ‘cage in’ the developing stems and take energy for the plant to maintain.
Remove any inedible tough leaves as you harvest and place them around the plants to top up the mulch, unless the leaves are diseased.
Towards fall it is possible to extend the growing season by allowing the outer leaves to get large, protecting the heart of the plant, while you harvest the younger inner leaves (making sure not to damage the growing point).
If grown for baby salad mix, chard will be ready to harvest 35 days after sowing.
Chard needs quick cooling and refrigeration storage after harvest. It stores well frozen if carefully blanched for 3 minutes, chilled, drained, and frozen in airtight containers.
Depending on who your customers are, you might need to label this crop clearly, and describe its wonderful features.
To keep chard in good condition over winter, either cover with hoops and row cover (in milder areas) or else mulch heavily right over the top of the plant, after cutting off the leaves in early winter.
Chard is hardy to 15°F (-10°C) without row cover.
Swiss chard is a great crop to grow, even if you don’t like its taste! Its benefits of being relatively low maintenance, attracting minimal pests and diseases, as well as being hardy and cold-resistant make it a must grow for your market garden.
It is also a great back-up if one of your other greens (like kale or spinach) takes a hit throughout the growing season.
Do your customers like swiss chard or do they prefer a different green? Please let us know in the comments below.
Kathy & Jon
your friendly neighbourhood growers