Grow Guide Conditions:
Celery and celeriac prefer cool summer climates and rich, loose soil with lots of organic matter. They must be kept consistently well fertilized and watered throughout the growing season to produce stalks and roots of size and mild taste. In hot climates, they are best started after mid-summer to mature in the cool fall weather.
Grow Guide Seed:
Celery is generally started indoors 10–12 weeks before transplanting because it takes a long time to germinate and grow seedlings large enough to plant. Sow the tiny seeds shallowly or on the soil surface of an open flat, ⅛ inch deep and about ¼ inch apart. Ideal soil temperature for germination is 65-75°F. Keep consistently moist. Transfer individual seedlings into 1½ inch cells when 2 true leaves are visible, then grow to 4-5 inches tall. Feed weekly with a diluted liquid fertilizer. Transplant outdoors after the last spring frost when weather is warm and settled, 6–8 inches apart, allowing 24-30 inches between rows. NOTE: Exposure of young seedlings to temps below 55°F over a few days can cause premature bolting. Harden plants by reducing water, NOT temperature, for a few days before transplanting.
Grow Guide Pests:
Rotate year-to-year to reduce leaf blight pressure. Maintain adequate soil calcium and moisture throughout season to prevent Black Heart. Control aphids to reduce or eliminate Celery Mosaic Virus. See our merchandise section for related products.
Grow Guide Harvest:
As soon as stalks are big enough, you can harvest a few outer stalks, but you may reduce the final plant size. Cut the whole plant at the base when it reaches full size, remove the leafy tops and store in the refrigerator. Harvest the celeriac roots at 3–5" in diameter, remove the leafy tops and trim the roots. Celeriac can be stored in the root cellar through the winter.