Learn About Swiss Chard
Swiss Chard FAQs
What’s the difference between Swiss chard and rhubarb? These are completely different plants. Sometimes Swiss chard is called rhubarb chard because the petioles look like rhubarb. Swiss chard is an annual leafy crop and the leaves and petioles (leaf stalks) may be eaten. Rhubarb is a perennial vegetable and the leaves are poisonous; we only eat the petioles.
Can I grow Swiss chard in containers? Yes, shorter varieties are fine for containers. Be sure to use a commercial potting mix rather than garden soil.
What part of the Swiss chard plant do we eat? We eat the leaves and stems, raw or cooked.
Can I start Swiss chard early indoors? We recommend sowing directly in the garden as Swiss chard grows quickly, but you can start indoors 6-8 weeks early if you wish.
Is Swiss chard a perennial? Swiss chard is a biennial and can tolerate cold temperatures. If you have a warm spell in winter you may be able to harvest some leaves. If it survives the winter you can harvest in spring until it produces a flower stalk.
Common Disease Problems
Basal Rot: This fungus invades through the roots and can infect the base of the petioles. It is more prevalent in warm, moist soils. Burpee Recommends: Avoid overwatering in warm months and provide good drainage. Contact your Cooperative Extension Service for recommendations.
Cercospora Leaf Blight: Small flecks which develop a yellowish halo appear on the leaves and turn brown and coalesce. They cause the leaves to wither and die. Burpee Recommends: Remove infected plants and destroy all plant debris. Rotate crops.
Curlytop: This is a virus disease that is characterized by yellowing, stunting and eventual death of plants. It is spread by leafhoppers. Burpee Recommends: Control the leafhoppers which spread the disease and remove and destroy infected plants.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water and rinse in a ten per cent bleach solution after use.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Leafhoppers: Leafhoppers cause injury to leaves and stunt growth. They also spread disease. Burpee Recommends: Remove plant debris. Use insecticidal soaps. Consult your Cooperative Extension Service for other insecticide recommendations.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage. Sanitation is important so be sure to remove all debris at the end of the season.
Lygus Bugs (Tarnished Plant Bug): Lygus bugs are ¼ inch long and are green or brown with yellow markings. Nymphs are flightless and smaller than the adults. They suck on stem tips and flower buds and inject a toxic that deforms roots and stems. Burpee Recommends: Because lygus bugs over winter in garden debris, remove all debris after the first frost. Contact your Cooperative Extension Service for insecticide recommendations.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs 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; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Harvest and Preserving Tips
- Begin harvesting leaves when they reach 5-6 inches or are large enough to use.
- Break off the outer leaves at their base, taking care not to damage the inner leaves.
- Plants that are harvested regularly will continue to produce new growth from the center of the plant.
- Both the leaves and stalks are edible raw, steamed, and sautéed, but avoid the lower 2-3 inches of the stalk as it may be fibrous and tough.
- Swiss chard may be blanched and frozen. Stems may be pickled.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating. Avoid disturbing the soil around the plants when weeding.
- Keep plants well watered during dry periods to promote rapid, uninterrupted growth. Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
- If flower stalk appears, remove it to prolong the harvest.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
How to Sow
- Sow in average soil in full sun spring as soon as ground can be worked.
- Prepare the bed by turning the soil under to a depth of 8 inches. Level with a rake to remove clumps of grass and stones.
- Sow about 6 inches apart and cover with ½ inch fine soil.
- Firm lightly and keep evenly moist.
- Seedlings emerge in 7-14 days.
- Thin stand to about 12 inches apart when seedlings are 1-2 inches tall.