Botanical Name: Apium graveolens
Days to Maturity: 100–120 days
Native: Africa, Asia, and Europe
Hardiness: Frost-tolerant biennial grown as an annual
Plant Dimensions: 18"–24" tall, 8"–10" wide; stalks: 10"–12" tall
Variety Information: Tall, dark green, thick, smooth stalks (leaf petioles). Blanching is not necessary with this variety, but growing at close spacing promotes a tender core and mild flavor. 'Tall Utah 52/70 Improved' is a stem or stalk type celery.
Attributes: Good for Containers
When to Sow Outside: Recommended for mild climates only. 1 to 2 weeks before your average last frost date, and when soil temperature is at least 50°F, or in fall for cool–season harvest.
When to Start Inside: RECOMMENDED. 10 to 12 weeks before your average last frost date for spring harvest, or 10 to 12 weeks before transplanting outdoors for fall crop. Biodegradable pots minimize root disturbance at transplanting. Optimal soil temperature for germination is 70°–75°F.
Days to Emerge: 15 – 30 days
Seed Depth: Press into surface
Seed Spacing: A group of 3 seeds every 6" – 12"
Row Spacing: 24"–36"
Thinning: When 1" tall, thin to 1 every 6" – 12"
Harvesting: Harvest outer stalks when they are at least 6" tall or harvest entire bunch when stalks have reached 10"-12". Cut with a sharp knife at the base. Harvest in the morning. Dunk celery in ice water and drain before storing to reduce field heat. If celery is bitter, refrigeration for 2 to 3 days will reduce bitterness.