A leafy green with a variety of rainbow-colored stems, Swiss chard is actually a beet without a bulbous root. Their leaves are tender and taste similar to spinach and beet greens, while their crunchy stalks taste like bok choy stems. It’s also loaded with vitamin K and vitamin A, and makes a great addition to your garden (and to your dinner plate.).
To help ensure your Swiss Chard thrives, we’ve put together this how-to video and transcript covering topics like:
Glossary of terms
Swiss Chard Varieties
Starting your Swiss Chard seeds
Caring for, fertilizing and/or Mulching
Transplanting best practices
Companion Plants do’s and don’ts
Common challenges and their Solutions
Pests, Diseases and what to do about them
Harvesting and storing your Swiss Chard
Listen to this Article
Glossary of Swiss chard terms
Before we get started, let’s learn a little bit about Swiss chard.
BOLTING
The premature production of a flowering stem (or stems) before the crop is harvested. It’s the plant’s natural attempt to produce seeds for reproduction. Swiss chard will not flower until the plant has lived through a winter, so there’s no danger of it bolting in the summer heat. However, some varieties will bolt prematurely if they’ve been exposed to prolonged freezing temperatures.
SEED CLUSTERS
Just like beet seeds, chard seeds actually come in clusters of a few seeds, which means that multiple seedlings will emerge from a single planting hole.
COMPOST TEA
Water that’s been steeped with compost, which will leach some of its nutrients and benefits into the liquid.
Varieties of Swiss chard
You’ve got a handful of colorful options to choose from.
BRIGHT LIGHTS
This type has dark green leaves on multicolor stems, and is bolt resistant but less frost tolerant.
Similar Varieties: Rainbow Just like it sounds, this type has red, pink, white, yellow, orange, and striped leaves and stems.
RHUBARB
A variety with dark green leaves and deep-red stems. You’ll want to sow Rhubarb after the risk of frost has passed, or else it might bolt.
Similar Varieties: Ruby Red This variety has green leaves and bright-red stems. Just like Rhubarb, you’ll want to sow it after the risk of frost has passed to prevent the risk of bolting.
FORDHOOK GIANT
This one has dark green leaves, white stems, and produces compact plants.
Similar Varieties: Lucullus A heat tolerant variety with green leaves and white stems.
PEPPERMINT
A bolt-resistant variety that’s great for containers, it has green leaves, and pink and white striped stems.
Starting your Swiss Chard Seeds
Keep in mind that direct sowing is your best bet, since transplanting can sometimes disturb the roots.
Swiss chard’s ideal soil temperature is between 50-85°F (10-30°C), and they prefer a soil with a pH between 6.0-6.5.
To speed up the germination process, soak your seeds in water for 24 hours before planting. This process can also help prevent soil rot and seed maggots from becoming an issue in cool, spring soil.
Then, plant your seeds in loose, rich, well-drained and deeply cultivated soil. You’ll also want to have wide rows or beds that get full sun.
You can sow your seeds about a half inch (1cm) deep, spaced about 4-12 inches (10-30cm) apart in rows that are 18 inches (45cm) apart.
Your seeds should sprout in 7-14 days, and you’ll want to use a floating row cover to then protect your seedlings from cold weather and insects.
Once the weather has warmed, be sure to remove the row cover or replace it with a lightweight mesh one.
That way, you don’t expose your plants to too much heat. A lightweight cover will still continue to protect your plants from pesky flea beetles and leaf miners.
Caring for Swiss Chad
In this section, we’ll cover everything you need to know about watering, thinning and weeding, plus how to fertilize and mulch your crop.
We’ll also talk about transplanting, companion planting, and your growing structure options.
THINNING
When your plants are a couple inches tall (about 5cm), thin them so that they’re about 4-6 inches apart (10-15 cm). Snip them with scissors and enjoy the young seedlings as a tasty snack.
WATERING
Water your Swiss chard evenly and consistently to help it grow better, making sure to water it often during dry spells in the summer.
Mulching your plants can also help conserve that much-needed moisture.
WEEDING
Remove all young weed seedlings by hand, and use a mulch laid along each side of the row to keep any weed seeds from growing.
PRUNING
To get the best quality Swiss chart, cut your plants back when they’re about a foot tall. If chard plants become overgrown, they become less flavorful – so cutting them back can help avoid that.
FERTILIZING AND/OR MULCHING
FERTILIZER
A liquid fertilizer or compost tea applied twice during the summer will help keep your chard growing well. Apply a half cup for each 10 foot of row using a nitrogen-based fertilizer (21-0-0 or 34-0-0).
You’ll want to apply this about 4 weeks after transplanting or thinning to encourage your plant to grow quickly. Place the fertilizer to the side of your plants, and then water it into the soil.
Another option is to use organic nitrogen, like blood meal or alfalfa meal. These help develop large, deep colored leaves.
Leaf applications with this option, along with liquid kelp, about 2-3 times during the gardening season will help boost your plant’s production.
MULCHING
You can use herbicide-free grass clippings, weed-free straw or another organic material.
Mulch to a depth of 3-4 inches to help prevent weed growth, which means you won’t have to cultivate as often.
TRANSPLANTING BEST PRACTICES
Swiss chard can be transplanted, though they do best when directly sown.
For summer crops, plant your seed indoors in early April or about 4 weeks before transplanting.
For fall crops, sow your seeds indoors in June. Room temperature should work just fine for germination, unless your house is particularly cool because of air conditioning. If that’s the case, use a heating mat to speed up the germination process.
Before you transplant, you’ll want to harden-off seedlings first by reducing their water and temperature. You’ll want to do this for 2-3 days before you plan to transplant.
Once they’ve been hardened-off, choose an overcast day to plant them in your vegetable garden. You’ll want to space them 4-6 inches apart, in rows that are 18-30 inches apart. Closer spacing will result in smaller, “baby leaf” plants, while farther spacing results in larger heads or plants.
GROWING STRUCTURE OPTIONS
RAISED BEDS
They should be at least 6-8 inches above your existing soil. Swiss chard needs full sun and regular water, and should be planted in rich, loose soil – so keep that in mind when using raised beds.
Before planting, work in 10-15 pounds of organic compost for each 100 sq. ft. to a depth of 8 inches.
Work the soil thoroughly, making sure to break up any large clumps while also removing any rocks.
CONTAINERS
They’ll need to have good drainage holes and a depth of at least 12 inches (30cm) for your Swiss chard to thrive.
Choose a smaller variety if you’re growing in containers, and trim the leaves as soon as they reach six inches (15cm).
This will encourage the leaves to grow more rather than the roots. Varieties like Peppermint do really well when grown in containers.
COMPANION PLANTS DO’S AND DON’TS
DO’S
Beans, Brassicas, and onions make the best companions for your chard.
It also grows well with other root crops like carrots, turnips, and parsnips. Spinach and kale also make great companions.
DON’TS
Butternut squash and spaghetti squash are not good companions for Swiss chard. You’ll also want to avoid planting corn, cucumber, melon, pumpkins, or potatoes nearby.
Common challenges and their solutions
There are a few pests and diseases that can potentially harm your Swiss chard. Not to worry – we’ve listed them below, as well as how to either avoid or fix the problem.
POTENTIAL PESTS
LEAF MINERS
These pests create irregular, round-shaped mines on the leaves. At first these mines are long and narrow, but eventually they’ll become an irregular-shaped patch.
Solution: Radishes attract leaf miners away from Swiss chard, so you can plant these together.
Also, natural enemies like certain parasitic wasps are known to help reduce their numbers.
Biological and cultural controls and sprays like AZA-Direct and Neemix can also help the issue.
APHIDS
These pests are particularly a problem on the undersides of leaves and/or on the stems of Swiss chard, and often feed in groups.
Solution: Use a strong jet of water to wash them off your plants. Neem oil, insecticidal soaps, and horticultural oils are also effective against aphids - just be sure to follow the application instructions on the packaging.
Oftentimes, you can also get rid of aphids by wiping or spraying the leaves with a mild solution of water and a few drops of dish soap (one variation includes adding a pinch of cayenne pepper).
Soapy water should then be reapplied every 2-3 days for about 2 weeks.
FLEA BEETLES
Small pests that are either black, bluish, bronze, gray, or sometimes striped. They jump when disturbed, and cause leaves to become wilted or have a “shot hole” appearance.
Solution: Sticky tape is an effective way to control these pests.
You can also try a homemade spray made up of five parts water, two parts rubbing alcohol and 1 tablespoon of liquid dish soap to fix your beetle problem
SLUGS AND SNAILS
These pests leave large holes in the leaves, or they eat them entirely. They leave behind a slime trail, feed at night, and thrive in damp weather.
Solution: If possible, hand-pick any slugs at night when they’re most active. You can also try attracting them to traps either using cornmeal or beer.
For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole. It’s best to use something with steep sides so that the slugs can’t crawl back out when they’re done.
Fill the bowl about three quarters of the way full with beer, and let it sit overnight. In the morning, the bowl should then be full of drowned slugs that can be dumped out for the birds to eat.
For a cornmeal trap, put 1-2 tablespoons of cornmeal in a jar then lay the jar on its side near your plants. Slugs are attracted to the scent, but they can’t digest cornmeal so it eventually kills them.
You can also try placing a barrier around your plants of diatomaceous earth (a natural powder made up of the skeletons of tiny aquatic creatures) or even coffee grounds, since they can’t crawl over these.
POTENTIAL DISEASES
CERCOSPORA LEAF SPOT
Small spots with light to tan centers will first appear on the older leaves of your plants. As the disease progresses, the centers of these lesions might become brittle and could possibly crack, while older infected leaves can yellow and die.
Solution: Don’t plant susceptible crops in the same spot more than once every three years.
Also, clean up and remove all plant debris at the end of the season. Also, apply a dense organic mulch (like grass clippings or compost) around your plants, then water around their base – not overhead.
Pick off any infected leaves, and if you have any plants that are badly infected, pull them out then hot compost them (a method that involves burning compost).
DOWNY MILDEW
This final disease forms a whitish or grey powdery substance that will appear on the leaves. Though it doesn’t look pretty, it’s not usually deadly – and it typically thrives in humid conditions or when there’s excess moisture.
Solution: Make sure to leave plenty of space between your plants to promote good air circulation.
Also, thin out your plant’s leaves, water at its base, and avoid getting the leaves wet.
You’ll want to avoid excess moisture Also, and be sure to water your Swiss chard only when needed, since it typically only needs to be watered during hot and dry weather.
Harvesting and storing
HARVESTING
Harvest your Swiss chard once the plants are about 9-12 inches high (23-30 cm). If you wait until they’re much taller, they’ll lose some of their flavor.
To harvest, you’ll want to cut the outer leaves first to allow the tender inner leaves to keep growing.
Be careful not to damage the terminal bud, which is at the center of the growing rosette of foliage, near the bottom.
Chard is best treated as a “cut-and-come-again” crop. This harvesting technique means you take only a few older leaves at a time from each plant, allowing the younger leaves to continue growing for future harvests later in the season.
If you prefer to harvest the entire plant at once, then we recommend planting additional chard seeds at 10-day intervals for about a month in the spring. That will ensure a more continuous harvest.
STORAGE
Swiss chard is extremely perishable, so keep in mind that you’ll have to eat it fairly quick after harvesting.
It stores best in very cold temperatures (32°F or 0°C) as well as in moist conditions (95% relative humidity).
Simply store your Swiss chard in a vented plastic bag and stick it in your fridge.