Add celery to the long list of edibles that I have no idea how to grow from seed. Just like the onion, I had to do my research. I almost didn't even attempt to grow them after reading that celery is one of the hardest vegetables to grow from seed. Ewww! However, I got some seeds in a trade so I decided to at least give it a try.
Besides, celery is on the dirty dozen list. Store bought (non-organic) celery is notoriously "dirty". It is very susceptible to leaching up chemicals in the soil it is grown in. Why not try growing my own organic celery? Another downside of the celery is that it has a very long growing season, often 4-6 months, and needs some TLC (blanching? what the heck?). I was still up for the challenge. Just like my notes on the onion, here are the tips and growing notes that I gathered on the celery.
Growing from Seed:
- For a summer crop, plant seeds indoors 8-10 weeks before the last spring frost (celery is very slow to germinate)
- Try soaking seeds overnight in warm water before planting to increase germination rates
- Sow 6 or more seeds per cell (celery has notoriously low germination rates) a few inches apart and only about 0.5 cm deep (shallow planting)
- Seeds need a temperature of at least 60-75 degrees F to germinate (use a heat mat or a heated greenhouse) for best results
- Germination may take up to a few weeks
- Once seedlings sprout, don't let the temperature dip below 50 degrees F or the celery will bolt (try to keep the temperature about 60-70 degrees F)
- Eventually, thin out all but the strongest plant in each cell
- Plant out transplants about 2 weeks before the last frost or when the seedlings have 4-6 true leaves and temperatures outside are above 50 degrees (if it's colder, celery will bolt)
- If you need to delay transplant time and want to slow the growth of your seedlings, trim plants down to 3 inches tall and allow them to continue to grow
- Full sun (at least 6 hours of sun daily)
- Long growing season: 4-6 months (some varieties can be found with shorter seasons)
- Grows best where there are long, mild growing season (optimal daytime temp below 75 degrees F and nights 50-60 degrees F)
- Celery is very susceptible to frost
- Set out transplants about 2 weeks before the average date of last spring frost in your area or when the seedlings have 4-6 true leaves and temperatures outside are above 50 degrees (if it's colder, celery will bolt)
- Spacing: Plant 6 inches apart
- Night time temperatures below 50 degrees longer than 5 days can cause celery to bolt
- Planting area: Soil should be rich, light & deep; direct sown celery can have deep tap roots (up to 4 feet); transplant seedlings don't go down that deep; amend soil at least 20 inches deep before planting; celery does not grow in clay soil
- Water: Keep evenly watered or plants will become very tough and stringy; Mulching may help with retaining moisture
- Fertilizing: Heavy feeder; 3 weeks before planting out celery, mix in plenty of compost and add lime if soil is too acidic (optimal pH=6.6-6.8); One planted, apply fertilizer every 2-3 weeks
- Blanching is the process of shielding the celery from sunlight during the growing season to keep the stalks light colored and give it a milder flavor. Many self-blanching celery varieties are available.
- Gardeners can blanch celery themselves by covering the stalks with bottomless milk cartons, newspaper or just tying the stalks together (inside stalks will be blanched). Just be sure not to cover the leaves of the celery (they need sunlight).
- You should start blanching celery about 10-14 days before harvesting
- Days to maturity (once transplanted outside): 120-140 days; some early varieties are 80 days
- Usually harvested mid-summer (about 3-4 months after transplanting into the garden) when the stalks about about a foot tall
- On the day of harvest, water celery really well before digging them up (this will keep them fresh and crisp for longer)
- Cut off the entire bunch below the base or use a fork to gently lift the whole celery plant (roots and all) or you can harvest stalks one at a time (insides will continue to grow)
- **All celery can cause a celery rash; wear gloves and long sleeves when harvesting to prevent this**
- Storage: Store in refrigerator for up to 2 weeks
Project Grow Celery from Seed
- Here are seedlings that I planted on January 23rd, 2011
- seeds were soaked overnight and placed on a heat mat with overhead lights
As with the onion project, I'll keep updating the Celery Project as long as my seedlings are kept alive!!
Celery Progress (seeds sowed 1/23/11):
Day 19 (2/11/11)