- Celery seeds should always be started indoors for the best success rate, 8 to 10 weeks before the average last frost date for your area.
- For summer gardeners, a late summer direct sowing is possible. Be sure that temps will stay between 55 and 70ºF throughout growing period.
- The National Gardening Association recommends soaking seeds in warm water overnight prior to planting, to reduce germination time.
- Work organic fertilizer or compost into the soil prior to planting.
- Harden off seedlings before transplanting by reducing water slightly, and keeping them outdoors for a couple hours a day.
- Transplant seedlings 10 to 12 inches apart, direct sow seeds ¼ inch deep. These will need to be thinned to 12 inches apart when they reach about six inches high.
- Mulch and water directly after planting.
- Celery is a heavy feeder. It also requires lots of water. Make sure to provide plenty of water during the entire growing season, especially during hot, dry weather.
- If celery does not get enough water, the stalks will be dry, and small.
- Add plenty of compost and mulch around the plants to retain moisture.
- Fertilize regularly. Add mulch as needed, to help retain soil moisture and add nutrients.
- Tie growing celery stalks together to keep them from sprawling.
- The parts of celery that are harvested are mainly the stalks, which will be above ground.
- 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. Note: 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.
- Keep celery in a plastic bag, in the refrigerator. It should be used within two weeks.