Celery

Apium graveolens (Apiaceae or carrot family)

Production

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Soil preparation

• Celery should not follow other members of the carrot family.
• Total nutrient uptake is 195 lbs. of N, 50 lbs. of P and up to 435 lbs. of K.
• Incorporate compost and plant celery in raised beds.
• Apply compost and other amendments based on the results of a soil test.
• 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. 
• Most vegetable crops remove little P, but at times your soil test result will call for additional P. Unfortunately, there aren’t short-term options for an organic grower to increase the available P levels in the soil. Through the use of animal-based fertilizers, P will build up to a level in the soil that is sufficient for all vegetable crops.
• 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. 

ommon recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
180	0-200	60-300	6.0-6.4
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

• Ventura, Kelvin, Tango

Greenhouse guidelines

• EZ Seeder seeding plate #13

Cell pack tray	Germination temp	Growth temp	Hardening off	Notes
288	70°–75°	60°–70°	Reduce water; no low temps	Put plug trays on a wire mesh bench to encourage air pruning. Exposure below 55° for 10 days or more causes bolting.

Transplant readiness indicators

• Harden plants off outside; plants that are lush don’t perform well in the field.
• When there are 2 true leaves, transplant to 72-cell trays.

Transplanting in 5- or 6-foot beds

Rows	In-row spacing	Planting depth (inches)	Notes
2	6-8 inches	Can be planted deeper than celeriac	Plant on your best ground.

Cultivation procedures

• Basket weed 7–10 days after transplanting, when weeds are still in the white thread stage and celery plants are established. 
• Use a finger weeder in combination with side knives for a second pass when new weeds emerge. Move finger weeders away from the crop if they cause damage. Alternatively, if you want very slight hilling, use spring hoes in combination with side knives.
• Hand hoe or hand weed between plants.

Insect and disease protection

• Common problems include a lack of nitrogen, calcium and boron. These can cause physiological disorders like hollow heart (not to be confused with celery anthracnose, as hollow heart is dry).
• You can prevent cutworms by spraying the soil with the beneficial nematode Steinernema carpocapsae. Once the pest is in the crop, control the population by spraying the crop with Bacillus thuringiensis kurstaki, or spread a baited product containing spinosyn, like Seduce, around the plants.
• Celery anthracnose is an emerging problem for celery growers in the Northeast. Its hosts include strawberries, garlic (including discarded garlic scapes) and fennel, so avoid rotating with these crops. It’s also hosted by weeds like red-rooted amaranth and lambsquarters. Avoid overhead irrigation. 
• Aster yellows is the most common issue affecting celery (and many other vegetable crops).
• Leaf hoppers transmit both celery anthracnose and aster yellows, so monitor for them. Place yellow sticky cards at plant height and check them at least twice a week.

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. 
• Celery, like celeriac, needs fertile ground with plenty of moisture and organic matter to do well.

Double cropping and/or cover cropping

• Work under any harvest remains to avoid insect or pathogen build up, and plant a cover crop. In the northern United States and Canada, you can follow summer- and early-fall-harvested celery with a cover crop of oats and peas in September, or rye and vetch planted at later dates. Adjust accordingly in other regions.

Harvest

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Ready-to-harvest and quality indicators

• Harvest when celery has fully developed, thick petioles (ribs) and is well formed.
• Harvested stalks should be free from blackheart, pithiness (spongy tissue on the inside of the leaf stalk), cracks, brown stem, soft rot doubles and damage or defects. Don’t harvest seed stalks. 

Harvest procedures

• Prompt pre-cooling to 32° is critical. (Hydrocooling with a chilled water spray is possible, with the appropriate equipment.)
• Wash hands and sanitize knives before harvesting.
• Harvest in the morning hours to avoid field heat accumulation.
• The plant is cut at the root. Hold the knife in a level position so the stalk being cut is nice and smooth at the bottom. If the immediate outside ribs are blemished, cut slightly higher so they are easily removed.
• A second person cuts off extra leaves in the field, trimming to the length of the box. The same person packs and loads on the truck.
• Properly harvested stalks are free from blemishes or soft spots when brought back to the pack shed, and only need some slight washing by spraying off the bottom part of the stalk.
• 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.

 Additional resources

• Production Guide for Storage of Organic Fruits and Vegetables 

Packing and storage summary for celery

Cleaning in the field	Remove damaged ribs and cut stalks to length of box.
Packing in the field	1 ⅓-bushel boxes, 20–24 stalks per boxes
Packing for delivery	The industry standard is a 24-, 30- or 36-count in a 1 ⅑-bushel box or celery box. See the International Federation for Produce Standards for the correct PLU code. Add the prefix 9 for organic crops.
Storage	At 32° and 95–100% humidity. Celery is not sensitive to ethylene exposure.

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.