Vegetable · Apiaceae
Celery
Apium graveolens var. dulce
Give it rich soil, cool weather, and water that never quits, and celery rewards the effort with crisp stalks.
Full sun
Every 2–4 days
55–64°F · 13–18°C
85–120 days
Overview
Celery has a reputation as the fussiest crop in the vegetable garden, and it earns it. This member of the carrot and parsley family wants steady cool weather, soil packed with organic matter, and moisture that never lets up, since the shallow roots dry out in a hurry. Get those right and the stalks come in crisp and clean.
It's a biennial grown as an annual, which is the root of much of its trouble. A long cool spell early on can convince a young plant it has already lived a year, and it bolts to seed instead of building stalks. That single quirk is why timing the transplant matters so much.
None of this makes celery impossible, just demanding. Treat it as a thirsty, slow crop that asks for rich ground and patience, and it pays you back over a long season from late summer into fall.
Care
The short version: full sun to a little afternoon shade, rich soil full of organic matter, and water that never runs short, kept in the cool 55°F to 64°F (13°C to 18°C) range it loves.
Light
Celery does best in full sun but takes a little afternoon shade, which actually helps where summers run warm. Too much shade leaves you with thin, weak stalks, so give it the open spot if you can.
Water
This is the part you cannot skip. Celery is shallow-rooted and thirsty, so it needs at least 1 to 2 inches of water a week and soil that never dries out. Let it go dry even briefly and the stalks turn stringy, pithy, and bitter.
Soil
Plant in rich, moisture-holding loam loaded with organic matter and dug deep, since the roots are shallow and need help staying damp. A pH of 5.8 to 6.8 suits it, and working in compost before planting pays off all season.
Temperature
Celery is a cool-weather crop happiest between 55°F and 64°F (13°C to 18°C). Heat pushes it toward bitterness and stress, while a long cold spell early on can make it bolt straight to seed.
Humidity
Ordinary outdoor humidity is fine, so there's no number to hit. Airflow is what counts here, because crowded, damp foliage is where leaf blight gets its start.
Feeding
Celery is a hungry feeder in soil already rich with organic matter. Give a balanced, nitrogen-rich fertilizer about every two weeks through the growing season, and keep calcium available so the hearts don't go black.
Pruning
There's little to cut. Pull off diseased or yellowing outer leaves and any side suckers, but never touch the central growing point. If you want milder stalks, blanch the outer ones for 2 to 3 weeks before harvest by mounding soil or wrapping them, though self-blanching types barely need it.
Repotting
Celery gets moved just once, from the seed tray out to the garden, and after that it stays put. It isn't usually grown in containers, so there's no potting up to manage through the season.
Size & spacing
Plants reach 18 to 35 inches (45 to 90 cm) tall with a fairly narrow footprint. Set them 12 to 18 inches (30 to 45 cm) apart, close enough to help blanch each other but open enough for air to move.
When to plant
Celery is a cool-season crop with a long road to harvest. Start the seeds indoors in late winter, set the plants out only once the worst chill has passed so they don't bolt, and cut the stalks from late summer into fall before a hard freeze.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 10 to 12 weeks before the last spring frost
- Plant: From about 2 weeks before to around the last spring frost, once soil has warmed and night temperatures stay above 50°F (10°C)
- Harvest: Late summer into fall; harvest stalks before a hard freeze
Hardiness
USDA hardiness zones: 3–10
Temperature: down to -40°C
Troubleshooting
Most celery problems show up in the stalks, and nearly all of them trace back to water or temperature. Catch the early signs and you can often steer the crop back on course. Match what you see below, then act before the whole plant turns.
A tall flower stalk shoots up and the stalks turn bitter
This is bolting, and it happens when young plants sit through a long cool spell that tricks this biennial into flowering a year early. Once a seedstalk rises the plant quits making good stalks, so cut what's still usable before it toughens and pull the bolted plant. The real defense is patience: harden off the transplants and set them out only after the danger of sustained chill has passed.
Fix:
- Harvest usable stalks promptly before they toughen
- Remove bolted plants
Blackened, dead tissue deep in the center of the plant
This is blackheart, and it comes from a calcium shortage in the fast-growing inner stalks rather than a disease you can spray off. Uneven watering and heat are what set it off, since the plant can't move calcium to the heart fast enough. Keep the soil steadily moist, side-dress with calcium, and salvage the healthy outer stalks while binning the rotted hearts.
Fix:
- Keep soil evenly and consistently moist
- Side-dress or foliar-feed with calcium
- Harvest unaffected outer stalks; discard rotted hearts
Spreading spots and browning blight across the leaves
This is fungal leaf blight, which takes hold when foliage stays wet and the soil drains poorly. Small spots enlarge and run together on the leaves and petioles, fastest in humid, soggy weather. Strip the affected foliage, open the planting up for better airflow, and keep water off the leaves.
Fix:
- Remove affected foliage
- Improve air circulation and avoid overhead wetting of leaves
Stalks that crack, string out, or go hollow inside
Stringy, pithy stalks almost always trace back to thirst, since celery hates any swing between wet and dry. A boron shortage or simply letting the plant stand too long past maturity can do the same. Restore even moisture, keep the soil fertile, and harvest on time instead of leaving stalks in the ground to coarsen.
Fix:
- Restore and maintain consistent soil moisture
- Harvest at proper maturity rather than letting plants stand
Toxicity
Celery is safe all around, both to eat and to grow near pets and children. The one thing to know is for the gardener: the leafy tops carry a natural compound called furanocoumarin that can leave sensitive skin red after you handle them in bright sun, so a quick rinse of the hands settles it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Safe to be around and safe to nibble. A cat that gorges on any plant might get a brief upset stomach, but celery itself is harmless.
Dogs None
A popular crunchy treat that does no harm. Some dogs urinate a little more after eating it, and a big serving may loosen the stomach, but neither is cause for worry.
Horses Safe
Horses can eat the stalks and leaves without trouble. Cut it into manageable pieces so a greedy eater doesn't choke.
Rabbits Safe
Rabbits enjoy celery and the leafy tops in moderation. Chop the stalks small so the long strings don't catch.
Livestock Safe
Goats, sheep, and cattle can graze celery and its trimmings with no ill effect.
Birds Safe
Chickens and other birds happily peck at chopped stalks and leaves, a fine bit of greenery for them.
People Safe
Celery is a kitchen staple, raw or cooked, with nothing to avoid in the eating. The one catch is handling: the foliage and sap carry furanocoumarins that can leave sensitive skin red and itchy after handling the tops in bright sun, so rinse your hands afterward.
Like other Apiaceae (parsnip, celeriac), celery foliage and sap contain furanocoumarins (psoralens) that can cause mild phytophotodermatitis in sensitive people who handle the tops in bright sunlight; this reaction is milder than with parsnip. Wash skin after handling the foliage and avoid prolonged sun exposure on contacted skin.
Varieties
Only a few celery varieties turn up in home gardens, and the main thing that sets them apart is how much blanching they need. These are the ones worth knowing.
Tall Utah (Utah 52-70 / Pascal type)
This is the standard dark-green pascal type with tall, crisp, compact stalks, and it's the classic celery most extension offices steer home gardeners toward.
Golden Self-Blanching
A compact early variety whose stalks pale to a soft yellow on their own, so you skip the trenching and wrapping that other types demand.
Tango
This hybrid is prized for tender, nearly stringless stalks and handles heat and uneven moisture better than the older varieties.
How to propagate
Celery is grown one way, from seed, and it's the slow, finicky start that earns the crop its demanding reputation.
SeedDemanding
Start indoors 10 to 12 weeks before the last spring frost · About 10 to 12 weeks to transplant size, then roughly 85 to 120 days from transplant to harvest
Celery starts from seed, and it tests your patience from the first day. Sow indoors 10 to 12 weeks before your last frost, surface-sow or barely cover the tiny seeds since they need light to sprout, and keep them warm at around 70°F (21°C) and never dry. Germination is slow and uneven, so soaking the seed first helps. From transplant it's another 85 to 120 days before the stalks are ready to cut.
Myths
Celery must be trenched and blanched or the stalks are inedible.
Blanching only softens bitterness and fades the green color. Green and self-blanching varieties are perfectly good to eat unblanched, so the whole trenching ritual is a choice, not a requirement.
A cut celery base set in water will regrow a full new bunch of stalks.
The base does sprout, but you only get small leafy regrowth that's handy for flavoring a pot. A real crop of stalks comes from seed-started plants, not from a stump on the windowsill.