Swiss Chard... and a Tuna Sandwich

by Jim Binnings, CCMGA Certified Master Gardener

As vegetable gardeners in Texas, we are fortunate to be able to garden year-round. However, as I’ve gotten older, working in the scorching summer heat is not my idea of fun. But give me fall, winter, and spring weather in North Texas, and I’m all in for vegetable gardening!

My favorite cool-season vegetable? A leafy green that’s both delicious and beautiful—Swiss chard. While it can be a bit finicky, I love growing and eating it for several reasons:

Great taste – I harvest leaves to eat raw with sandwiches and salads, or chop them into soups and stews.
Attractive plant – Swiss chard works as both a vegetable and an ornamental annual in flower beds. *(Note: If planted with annual flowers, avoid eating it since flower beds may have been treated with gardening chemicals.)*
Nutritional powerhouse – A cup of cooked Swiss chard provides 477% of the daily value (DV) of vitamin K, 60% DV of vitamin A, 35% DV of vitamin C, and 22% DV of vitamin E. It’s also rich in magnesium, copper, iron, potassium, and calcium.*
Ideal for small spaces – Swiss chard thrives in patio planters if you're a container gardener.

*Daily value information from Healthline.com

A Bit of Background
Swiss chard belongs to the beet family (Chenopodiaceae), though it doesn’t produce an edible root. Its leaves resemble beet greens, and in New Zealand and Australia, it’s known as silverbeet. Native to the Mediterranean, it was cultivated even before the Roman Empire. At one time, Swiss chard was the star of Christmas Eve meals in southern France because its petioles (stems) taste similar to artichoke hearts.

How to Grow Swiss Chard

When to Plant
For a spring harvest – Plant seeds 2-4 weeks before the last frost (around March 12 in North Texas).
For a fall harvest – Plant seeds 4-6 weeks before the first freeze (around November 22 in North Texas).

Planting from Seed
- Soak seeds overnight before planting for better germination.
- Plant ½ inch deep, 3-6 inches apart.
- Start in pots for later transplanting if desired.

Growing & Harvesting
- Once plants reach 3-4 inches tall, thin them to 6 inches apart.
- Apply a balanced fertilizer mid-season (though Swiss chard isn’t a heavy feeder).
- Water 1-1.5 inches weekly and mulch to retain moisture.
- Harvest leaves when they reach bread-slice size—perfect for tuna salad sandwiches!
- Harvest from the outside in—Swiss chard is a "cut and come again" plant, meaning new leaves will regrow.
- If the plant starts to bolt, pull it, as no new leaves will form.

Best Varieties to Grow

Bright Lights – Dark green leaves, multicolor stems; bolt-resistant but less frost-hardy.
Fordhook Giant – Dark green leaves, white stems; compact and heat-tolerant.
Rainbow – Colorful red, pink, white, yellow, orange, and striped stems.
Ruby Red – Green leaves with bright red stems; best planted after the risk of frost.

Is Swiss Chard Finicky?
Yes, but with the right conditions, it thrives! A hard freeze (mid-20s°F) can knock it back, though it may regrow if temperatures warm up. On the other hand, Texas summers can be tough on chard, and it struggles past mid-June without shade.

One exception. Fordhook Giant! Last summer, one of my Fordhook chard plants grew all season long, thriving in partial shade from mid-afternoon to sunset. While some say chard turns bitter in the heat, I can personally confirm—Fordhook tasted just fine on my tuna sandwiches all summer!

If you love leafy greens, give Swiss chard a try. Bon appétit!

Additional References:
https://www.healthline.com/nutrition/swiss-chard
https://hort.extension.wisc.edu/articles/swiss-chard/
https://www.almanac.com/plant/swiss-chard