How to Grow Giant Prague Celeriac
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Giant Prague Celeriac
Apium graveolens var. rapaceum
vegetableGiant Prague is a celery root (celeriac) variety prized for its large, knobby white roots that can reach 4-5 inches in diameter. The plant develops edible leafy greens above ground and a substantial underground bulbous root with a mild celery flavor. It's a cool-season crop requiring a longer growing season than regular celery.
When should you plant Giant Prague Celeriac in your zone?
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Example Giant Prague Celeriac timeline · Pittsburgh, PA (Zone 6b)
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Plant Giant Prague Celeriac
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Giant Prague Celeriac
Around Aug 5≈ 110 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Giant Prague Celeriac dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-8; prefers cooler climates with consistent moisture
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Seed Germination & Seedling
3-4 weeksTiny seeds sprout slowly (14-21 days); seedlings develop first true leaves and thin taproots. Very delicate stage.
Keep soil warm (65-75°F) and consistently moist. Start indoors 10-12 weeks before transplanting. Provide bright light to prevent leggy seedlings.
Early Growth & Transplanting
2-3 weeksSeedlings develop several true leaves and stronger root systems; ready for hardening off and outdoor transplanting.
Gradually expose to outdoor conditions over 7-10 days. Transplant when 2-3 inches tall and showing 3-4 true leaves. Handle gently to avoid damaging roots.
Vegetative & Root Development
6-8 weeksPlant develops sturdy leafy crown above ground while root bulb begins swelling underground. Moderate foliage growth and gradual root expansion.
Maintain consistent watering and moisture. Apply 2-3 inches of mulch around base. Begin fertilizing every 3-4 weeks with balanced or root-promoting fertilizer. Remove any flower stalks if they appear.
Bulb Maturation & Root Enlargement
4-6 weeksUnderground celeriac root grows significantly larger, developing the characteristic knobby appearance. Foliage becomes denser and darker green.
Continue consistent watering; do not allow soil to dry out. Keep soil evenly moist but avoid waterlogging. Reduce nitrogen fertilizer, increase potassium to promote root quality. Thin foliage if too dense to improve air circulation.
Harvest Readiness
Ready to harvestRoots reach 4-5 inches diameter (Giant Prague's signature size); skin firms up and roots are firm and heavy. Peak flavor and texture achieved.
Stop heavy watering 1-2 weeks before harvest to reduce cracking. Roots can be left in ground in cool climates or harvested and stored. Gently loosen soil around plant before pulling.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove affected leaves; use floating row covers; encourage beneficial insects; insecticidal soap if severe
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Use row covers until plants are 4 inches tall; companion plant with onions and carrots; remove affected roots
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Increase humidity and misting; use neem oil or insecticidal soap; encourage predatory mites
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and
Hand-pick; set beer traps; use diatomaceous earth; encourage ground beetles
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Strong water spray; neem oil; insecticidal soap; encourage ladybugs
Uses
Roasting & Soups
CulinaryGiant Prague roots are excellent roasted until creamy, added to soups for celery-like flavor, or mashed as a side dish. The large roots provide substantial yields for cooking. [source]
Fresh & Cooked Greens
CulinaryYoung leafy greens are edible raw in salads or cooked as greens. The root itself has a mild celery flavor suitable for raw celery root salads or celery remoulade. [source]
Nutritional & Digestive Support
MedicinalCeleriac is high in vitamin C, potassium, and fiber, supporting immune function and digestive health. Traditionally used to support kidney and liver function. [source]
Root Vegetable Storage & Preservation
HouseholdGiant Prague roots store excellently for months in cool conditions, providing a reliable winter vegetable. Can be fermented, roasted and frozen, or kept fresh in root cellar storage. [source]
Pollinator Support
WildlifeIf allowed to flower, celeriac produces small umbrella-shaped flower clusters (umbels) attractive to beneficial insects and pollinators. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest when roots are 4-5 inches in diameter (typically 110-130 days after transplanting). Roots can be left in ground in cool climates until first hard frost. Gently dig around the plant and pull from the base. In cold climates, can be left in ground with heavy mulch protection and dug as needed through fall. Harvest entire plant including the knobby root; foliage is also edible. Store roots in cool (32-40°F), humid conditions for 2-3 months.
Fun Facts
- 🌱 Giant Prague is a heirloom variety with documented cultivation dating back to the 1800s, originally developed in Prague and exported worldwide for its exceptional root size and storage quality.
- 🌱 The entire plant is edible—not just the root. The leafy greens develop edible foliage similar to celery leaves with a slightly stronger celery flavor.
- 🌱 Celeriac is called 'celery root' in English but 'céleri-rave' in French and 'Knollensellerie' in German, reflecting its different name across culinary traditions worldwide.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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