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Celery: How to Plant, Grow, and Harvest Celery Stalks | The Old Farmer's Almanac

Celery

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Alfredo Maiquez/Shutterstock
Botanical Name
Apium graveolens
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Planting, Growing, and Harvesting Celery

Catherine Boeckmann
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Not only is garden celery better-tasting than store-bought types, but it’s also less chemical-laden. In cooler regions, it does best planted in the early spring. In warmer areas, plan to plant in mid- to later summer. Here’s our advice on planting, growing, and harvesting celery!

About Celery

Although one of the more difficult crops to grow at home, celery always has a place in our gardens because it’s so useful in the kitchen—for stews, stir-fries, soups, and salads. 

This cool-weather, long-season crop can require up to 140 days to come to harvest, although short-season varieties are available. Celery is considered a hardy biennial, but it’s typically grown as an annual for its edible 12- to 18-inch stalks. Celery is considered a relatively difficult crop, as you do need start celery from seed indoors (transplants are hard to find and do not always succeed) and the plant is prone to bolting in cold weather.

There are two types of celery available:

  1. Trenching celery needs soil mounded up against the stems as they grow to produce crisp, pale stems. To make this easier, trenching celery is typically planted into trenches, hence the name, but some gardeners aid this blanching process using cardboard tubes, pipes or collars.
  2. Self-blanching celery requires none of these extra steps. This makes it a lot easier to grow, and the stems are just as tasty!

Enjoy our video all about growing celery and then follow the planting, growing, and harvesting instruction below

Planting

When to Plant Celery

  • Due to its need for a long growing season, it’s best to start celery seed indoors. 
    • For a spring crop, start seeds 10 to 12 weeks before your last spring frost date.
    • For a fall crop, start seeds in time to transplant seedlings 10 to 12 weeks before the first fall frost date.

Choosing and Preparing a Planting Site

  • Select a site that receives full direct sunlight. 
  • Celery needs compost-enriched soil. Loosen the soil to a depth of 12 to 15 inches with a garden fork or tiller. Mix 2 to 4 inches of aged manure and/or compost into the soil, or work in some 5-10-10 fertilizer. The soil should retain moisture, bordering on wet but still draining.
  • Celery prefers a soil with a pH between 5.8 and 6.8. Get a soil test if you’re not sure of your soil pH.
  • It’s important for celery to grow in moisture retentive soil that doesn’t drain too quickly. Wild celery grows in boggy ground, so you’ll need to ensure consistent moisture for this thirsty vegetable, while a sunny spot should ensure good, even growth.

How to Plant Celery

Starting Seeds

  • Before sowing, soak seeds in warm water overnight. This will speed germination. The seeds are tiny, so handle with care and a keen eye!
  • Fill seed flats or pots with good-quality seed starting mix then gently firm it level.
  • Press soaked seeds into seed-starting soil; to get good germination, do not cover with soil. The easiest way to sow the seeds is to carefully tap the packet above the surface of the potting mix and watch carefully as the seeds fall. Ideally you want them to fall about an inch apart. Once you’re done, firm the seeds into place.
  • Cover starter trays/pots with plastic wrap to retain moisture. Germination should occur in about a week but it can take up to three weeks; be patient.
  • Soon after seedlings appear, place a fluorescent grow light 3 inches above them for 16 hours a day (plants need dark hours, too).
  • Maintain an ambient temperature of 70° to 75°F (21° to 24°C) during the day and 60° to 65°F (15° to 18°C) at night. 
  • Mist regularly.
  • When seedlings are 2 inches tall, transplant them to individual peat pots or to deeper flats with new potting soil. In flats, set the plants at least 2 inches apart.
  • Harden off seedlings before transplanting by reducing water slightly and putting them outdoors (in a sheltered spot protected from the sun) for a couple of hours each day.

Transplanting Outdoors

  • Plant celery outdoors when the soil temperature reaches at least 50°F (10°C) and nighttime temperatures don’t dip down below 40°F (4°C). (Cold weather after planting can cause bolting.)
  • Plant seedling 8 to 10 inches apart.
  • Water thoroughly. 
Growing

How to Grow Celery

To grow well, celery has three critical needs:

  1. Cool weather; celery won’t tolerate high temperatures.
  2. Constant water; stalks will be small, stringy, tough, and/or hollow if it goes without water.
  3. Soil that’s rich in organic matter and—because its roots are shallow (just a few inches deep)—fertilizer applied on top of the soil.
  • Make sure to provide plenty of water during the entire growing season, especially during hot, dry weather.
  • Use row covers for the first 4 to 5 weeks in order to protect from pests.
  • When plants are 6 inches tall, mulch around them to keep the soil moist and roots cool.
  • Side-dress with compost. Comfrey pellets are great, as are coffee grounds, tickled into the soil between plants. 
  • In the second and third months of growth, side-dress with 1 tablespoon of a 5-10-10 fertilizer 3 to 4 inches from each plant.
  • Keep celery weed-free, but be careful when weeding as celery has shallow roots that could easily get disturbed.
  • Tie growing celery stalks together to keep them from sprawling.
  • Start earthing up trenching varieties once the stems reach about a foot tall, banking the soil up by about three inches (8cm) each time until you can hill up no more.
  • Blanch (wrap or cover) stalks to eliminate any bitter taste and produce pale green stalks. Use anything that will keep out light: brown-bag paper or cardboard (secure with old nylon stockings, string, vegetable wires), half-gallon milk cartons (cut out tops and bottoms), or the like. Do not cover the celery’s leaves.

celery-shutterstock_262679072_full_width.jpgImage: Garden celery. Photo credit: Yuris/Shutterstock.

Harvesting

How to Harvest Celery

  • Harvest celery from summer and through the autumn until the first hard frosts stop growth. As a biennial, celery may overwinter in milder climates, producing occasional stems throughout the coldest months and picking up again in spring before finally stretching to flower.
  • You can harvest plants whole, but cutting or picking individual stems as required will keep plants producing over a longer period.
  • The parts of celery that are harvested are mainly the stalks, which will be above ground.
  • Pick the stalks whenever you want. Young celery is as good as the mature product.
  • Harvest stalks from the outside in. You may begin harvesting when stalks are about 8 inches tall.
  • Celery can be kept in the garden for up to a month if soil is built up around it to maintain an ideal temperature. Celery will tolerate a light frost, but not consecutive frosts.
  • Tip: The darker the stalks become, the more nutrients they will contain. Texture changes with color; dark green stalks will be tougher.

How to Store Celery

  • Keep celery in a plastic bag in the refrigerator. Celery stores really well; you can keep it for many weeks with no trouble. 
  • Celery stalks can be frozen. Cut the stalks into half-inch pieces and store in freezer-grade bags.
Wit and Wisdom
  • Keep in mind the grocery store celery is lighter in color and bigger than homegrown celery because the commercial varieties are grown in greenhouses and/or protected from the sun; they may carry a lot of pesticides, too. 
  • Nibbling on celery after a meal helps to clean your teeth and mouth.
  • To crisp limp celery, soak it in cold water with a few slices of potato.
  • The ancient Romans believed that celery had healing powers, especially when it came to headaches. It’s also been thought to cure a hangover, toothache, or arthritis, and serve as an aphrodisiac.
  • Bland or boring? You may be delighted to discover that celery has many benefits. See why celery is heathy and happening.
Pests/Diseases

Celery is relatively trouble-free. To control pests early on, cover the plants with garden fabric (row covers) during the first four to six weeks of the growing season

Celery Pests and Diseases

Pest/Disease Type Symptoms Control/Prevention
Carrot rust flies Insect Wilted/stunted plants; tunnels with rust-color excrement in roots of carrot-family crops; root rot Monitor adults with yellow sticky traps; use row covers; add native plants to invite beneficial insects; destroy crop residue; rotate crops
Earwigs Insect Many small holes in leaves/stalks Trap in tuna can filled with 1/2 inch of fish oil and sunk in soil such that edge is slightly above ground level; remove plant debris and other nearby hiding places
Flea beetles Insect Numerous tiny holes in leaves (looks like leaves were hit by birdshot) Use row covers; mulch heavily; add native plants to invite beneficial insects
Mosaic virus (cucumber) Virus Varies, but may include stunting, mottled green/yellow/white pattern or ringed spots on leaves; distorted leaf growth Destroy infected plants; choose resistant varieties and certified virus-free seed; use row covers; disinfect tools; weed; control aphids (virus carriers); use mulch
Slugs/snails Mollusk Irregular holes in leaves; slimy secretion on plants/soil; seedlings “disappear” Handpick; avoid thick bark mulch; use copper plant collars; avoid overhead watering; lay boards on soil in evening, and in morning dispose of “hiding” pests in hot, soapy water; drown in deep container filled with 1/2 inch of beer, or sugar water and yeast, and sunk so that top edge is slightly above ground; apply 1-inch-wide strip of food-grade diatomaceous earth as barrier

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