Chard, Swiss

Beta vulgaris (cicla variety) (Chenopodiaceae or goosefoot family)

Production

Soil preparation

Swiss chard should not follow after spinach or beets, but later plantings do very well after early peas or lettuce.
Total nutrient uptake is 105 lbs. of N, 16 lbs. of P and 160 lbs. of K.
Apply compost and other amendments based on the results of a soil test. Incorporate compost and plant chard in raised beds.
Spread lime as needed to increase both the pH and Ca levels. Dolomite lime will also increase Mg levels. Spread gypsum when calcium levels are low but pH is correct.
A fertilizer company can add OMRI-listed potassium sulfate to compost if it doesn’t have enough K to meet the crop’s needs. If this isn’t possible, spread the correct amount of fertilizer and incorporate it before planting. Alternatively, you can side-dress it during cultivation. Divide the recommended rate of the soil test in half if side-dressing.
Test for boron and apply only as recommended by the soil test. A fertilizer company can add boron to compost to optimize boron distribution. If this isn’t an option, distribute soluble boron through a water solution with a sprayer directly on the soil. If applied directly on the crop don’t exceed more than 1 lb. of boron per acre to avoid leaf burn.
Jang, Sutton Jr. or Planet Jr. planters in combination with small seeds like Swiss chard don’t perform well with plant matter on the soil surface, so avoid planting them after tall green manures.
When direct seeding Swiss chard, create a fine and firm seedbed chard to facilitate good seed-to-soil contact.

Common recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
100	0-160	0-200	6.2-6.5
¹Rates are for New York and are from Cornell University’s Nutrient Guidelines for Commercial Vegetable Production (2019). Check the Cornell website for updated guidelines, or consult with local experts for recommended rates outside New York.

Varieties

Washington State variety trial
Bright Lights has become a standard on many vegetable farms, but Golden Sunrise, Magenta Sunset, Fordhook Giant, Rhubarb Supreme and Oriole are common as well.

Direct seeding information

Seeder	Rows	Seeds per foot	Seed plate no.	Depth (inches)	Sprocket setting	Notes
Planet Jr.	3 or 5	50	22	Depth 2-3
MaterMacc	5-9	35	24	1/4-1/2		0.8 mph (when harvested for braising mix)
Jang	3 or 5	6-24	LJ 12	1/4-1/2	See notes	The sprocket setting depends on how you harvest the crop. Use front 11/rear 13 for individual stems, or front 14/rear 9 for loose leaf.

Greenhouse guidelines

EZ Seeder seeding plate #9

Cell pack tray	Germination temp	Growth temp	Hardening off	Cell pack tray
72, 98 or 128	75°-90°	65°–75°	Reduce water	2-3 seeds per cell. Put plug trays on a wire mesh bench to encourage air pruning. Take plants outside 1 week before planting in field.

Number of successions

For single harvest, plant each succession when the cotyledons are up on the previous planting. Generally, allow 10–14 days between the first and second succession, and end with intervals of 7 days for continuous harvest.
When harvesting multiple times from the same plants, reduce the number of successions accordingly.

Signs to watch for and what to do

Watch that plants don’t start to get leggy from too much warmth and lack of light.
Harden plants off outside; plants that are lush don’t perform well in the field.

Transplant readiness indicators

Plants should come easily out of their cells. Generally plants shouldn’t be older than 4 weeks.

Transplant tips

You can also transplant chard using a paper-pot planter, which allows you to get optimum spacing and an early start. Start paper pots in the greenhouse. This results in a high germination rate. Chard seed contains more than 1 seed, and pot spacing of 6 inches (LP303-15) is optimal for easy picking. Plant when Swiss chard has developed its first true leaves. Planting later leads to transplant shock. Don’t bury the plants, but make sure the pots themselves are covered to avoid drying out. Irrigate the first week until roots are established.

Transplanting in 5- or 6- foot raised beds

Rows	In-row spacing	Planting depth (inches)	Notes
3	5 inches	Don’t bury the plug; the top of the plug should be level with the soil to avoid leaves touching the soil.	Tends to have transplant shock; plant in late afternoon to avoid burning plants.

Cultivation procedures

Basket weed 7–10 days after planting. Use a basket weeder or wheel hoe when weeds are in the white thread stage. Weed control is more effective when you eliminate weeds before they emerge.
Hand hoe between plants.
Use a finger weeder in combination with side knives for a second pass when new weeds emerge. Alternatively, if you want very slight hilling, use spring hoes in combination with side knives. These tools effectively eliminate small weeds.

Frost, disease and insect protection

Leaf miners can be a serious issue for Swiss chard. Use row covers or insect netting to prevent the adult fly from laying its eggs on the crop. If row covers or insect netting aren’t options, place yellow sticky cards at plant height and check them at least twice a week. Otherwise, look on the underside of the leaves for any eggs. In the northern United States, there are generally 3 generations of adult flies laying eggs. Once the eggs hatch, or when you see the first signs of damage, apply a spinosyn-based product like Entrust every 5–7 days, not to exceed 3 sprays.
Cercospora leaf spot is best controlled by practicing multi-year rotations that don’t include any member of the Chenopod family, along with a good program to control weeds like lambsquarters. Other plants, like sweet clover, can be a host of this pathogen. Applying Bacillus amyloliquefaciens, as in the product Double Nickel, has been observed to have efficacy. Application of Reynoutria sachalinensis, which is an extract made from giant knotweed (as in Regalia), has shown some efficacy as a preventive schedule.

Other cultural practices

Irrigate frequently for optimum yield and plant health. Frequency depends on soil type, evaporation, precipitation and the particular needs of the crop.

Double cropping and/or cover cropping

Don’t plant another cash crop after early chard, as its roots will regrow and act as a weed. Establish a cover crop after working the ground with a disc and harrow.
For later dates, work under any harvest remains to avoid insect or pathogen buildup, and plant a cover crop. In the northern United States and Canada, you can follow summer- and early-fall-harvested chard with a cover crop of oats and peas in September, or rye and vetch planted at later dates. Adjust accordingly in other regions.

Harvest

Yield	An average of 1 marketable bunch per row foot. Higher yields are possible when making multiple cuttings but the quality diminishes over time.
Standards	Harvesting¹ 60–80 bunches per person, per hour. Half the labor is needed when harvesting loose instead of in bunches.
Standards	Washing 240 bunches per person, per hour
Tools and supplies needed	Sharp clean knives, 1 ⅓-bushel boxes and rubber bands or twist ties (customer preference may influence this).
¹Harvest rates don't include the time required to transport crops from the field to a wash and pack shed or storage facility.

Ready-to-harvest and quality indicators

Plants are 15–18 inches tall, and the bottom leaves are large enough to make a bunch.
Chard has good color and is free from yellowing leaves, old stems or damage from leaf miners.

Harvest procedures

Wash hands and sanitize knives before harvesting.
Harvest in the morning hours to avoid field heat accumulation.
The harvest boxes you use in the field should be different from the boxes you pack for distribution.
Hold onto all the leaves you will put in the bunch before cutting close to the ground.
Inspect the bunch for dead or diseased leaves and discard them.
Or, for better bunches and regrowth, pick chard leaves individually. One bunch will contain about 5 mature leaves.
Place a twist tie or rubber band around the bunch and make one final straight cut to make the bunch the length of the box.
Layer the bunches in the crate lengthwise, alternating the direction of the leaves.

Washing and storage procedures

Wash hands and rinse boots before entering the wash-and-pack shed, and cover up field clothes with a bib. If a long-sleeve shirt contains soil, remove this as well.
Add a sanitizer to the wash water. Use the guide How to Wash Produce Using a Peracetic Acid Solution to establish how much peracetic acid solution to add to water.
Wash chard at least twice in clean tubs. You can use the last dunking to hydrocool the product by adding ice to the water or by having the water pre-cooled.
Don't leave bunches in water for longer than 1 minute, or until the core of the stems are properly cooled down. Chard can get waterlogged after a few minutes, which causes the leaves to deteriorate faster.
Pack in sealed boxes or line the boxes with a plastic liner to avoid having the product lose moisture during longer storage.

Additional resources

Production Guide for Storage of Organic Fruits and Vegetables

Packing and storage summary for swiss chard

Packing in the field	Plastic 1⅓ bushel boxes
Packing for delivery	24 bunches or 20 lbs. per regular 1 ^⅑ waxed bushel box See the International Federation for Produce Standards for the correct PLU code. Add the prefix 9 for organic crops. Use a clean box of choice for CSA distribution.
Storage	SAt 32°–41° and 95–100% humidity. Pack in closed containers for improved storage. Swiss chard is highly sensitive to ethylene exposure. Allow for good air exchange and don’t store with crops that release ethylene.

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture through the Sustainable Agriculture Research and Education (SARE) program. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.