How to Grow Celery From Seed

Celery is a cool-season crop with a long, slow schedule, so plan backward from your last spring frost. Start seeds indoors about 10 weeks before that date, because germination is slow and the plants need a big head start. Move seedlings out only after the danger of frost has passed and nights stay above about 50F, since a hard cold snap can trick young celery into bolting later. In mild-winter areas it also does beautifully as a fall and winter crop, sown in late summer to mature in the cool months.

Celery seeds are tiny and need light to sprout, so surface-sow them: scatter the seeds over moist seed-starting mix and press them in gently, without covering. Soaking the seeds overnight first helps them along. Keep the tray at 70 to 75F and constantly moist, and be patient, because germination takes 14 to 21 days. Transplant seedlings into their own pots once they are a couple of inches tall, then harden them off and set them in the garden 6 to 8 inches apart in rows about 2 feet apart. Celery is a heavy feeder that loves rich, moisture-holding soil, so work in plenty of compost before planting.

Celery has one non-negotiable rule: never let it dry out. It has shallow roots and a big appetite, so water deeply and often to keep the soil constantly moist, mulch to hold that moisture, and feed every couple of weeks with compost or a balanced fertilizer. Steady, uninterrupted growth is what gives you tender, sweet stalks instead of stringy, bitter ones. Climate really sets the pace here: in hot regions like Texas, Florida, and the Deep South, grow celery as a fall-through-spring crop, since summer heat above the mid-80s stresses it and hot spells after a cold start can trigger bolting. In cooler places like the Pacific Northwest, the Northeast, and the upper Midwest, a long spring planting or a fall crop suits its love of steady, mild weather.

Celery is slow and low, which leaves room for good neighbors that guard it and fill the gaps. These four make especially good companions, and you can add any of them in one click:

You can start picking outer stalks once they are about 8 inches tall, cutting them at the base and leaving the center to keep growing, or wait and harvest the whole head by cutting it at soil level. For milder, sweeter stalks, blanch the plant in its final week or two by wrapping the stalks with newspaper or mounding soil around them to block the light, leaving the leafy tops exposed. Do not toss the leaves, they carry a concentrated celery flavor and are great in stocks and salads.

Homegrown celery is more fragrant and flavorful than the supermarket kind. Dice the stalks with onion and carrot for the mirepoix that starts soups, stews, and stuffing, or chop them into salads, tuna, and chicken salad for crunch. Eat the ribs raw with dips, braise them as a side, or juice them. Save the leaves for stocks and garnishes, and let a plant go to seed to harvest celery seed for spice blends and pickling.

• Slow or patchy germination: soak seeds overnight, surface-sow without covering since they need light, and keep the mix at 70 to 75F and constantly moist.
• Stringy, bitter stalks: caused by dry soil, heat, or slow growth. Water steadily, feed regularly, and blanch the last week or two.
• Bolting: a cold snap after transplanting, or summer heat, makes celery flower early. Wait for settled warm nights to plant out and grow it in the cool season.
• Cracked or hollow stalks: usually uneven watering or a boron shortage. Keep moisture even and the soil rich in organic matter.