Apium graveolens

Sowing and cultivation notes

Apium graveolens seeds germinate best with steady moisture and light; sow indoors well before last frost, barely covering the seed. Provide bright conditions and gentle warmth. Transplant after frost once the soil is warming, spacing plants to allow good air flow. Choose full sun to light shade and a rich, moisture‑retentive yet well‑drained soil, improving the bed with organic matter. Keep growth even with consistent watering and a mulch to reduce evaporation. In mild climates, an autumn sowing supports cool‑season development. Harden off gradually and avoid checks to growth that can trigger bolting. Medium height at maturity; feed lightly during the season if soils are poor.

• Sow finely; surface‑sow or barely cover, as light aids germination; keep evenly moist, not waterlogged.
• Start indoors well before last frost; transplant after frost when soil is warming; autumn sowing possible in mild climates.
• Full sun to light shade; rich, moisture‑retentive, well‑drained soil; incorporate organic matter.
• Allow generous spacing for airflow; harden off; mulch to conserve moisture and steady growth.
• Edible: stems and leaves can be used in cooking once plants are mature.

How do I grow Apium graveolens (celery) from seed?

Sow celery indoors because it is slow to start. Surface-sow or cover very lightly, as the tiny seeds germinate best with light, and keep the medium evenly moist at a gentle warmth. Prick out to modules once seedlings have two true leaves, grow on in bright conditions, and harden off gradually. Transplant after all frost has passed and the soil is warming. Choose a site in full sun to light shade with rich, moisture-retentive yet well-drained soil improved with organic matter. Space for good airflow, mulch to conserve moisture, and keep growth steady with consistent water and modest, regular feeding.

When should I start celery indoors?

Start celery indoors well before the last frost—often around 10–12 weeks ahead—so seedlings are sturdy by transplant time. Germinate at mild warmth, then keep plants growing without checks. Transplant outdoors only after frost has passed and nights are reliably mild, when soil is workable and beginning to warm. In areas with mild winters, an autumn sowing can provide cool‑season growth. Avoid exposing young plants to prolonged chill after they have a few leaves, and provide ample light (supplementary light if needed) to prevent legginess while they wait for planting out.

What soil is best for celery plants?

Celery thrives in fertile, moisture‑retentive but well‑drained soil enriched with plenty of well‑rotted organic matter. Aim for a friable texture that holds water evenly without becoming waterlogged; raised beds are fine if they do not dry out. Incorporate compost before planting and top up with an organic mulch to stabilise soil moisture and temperature. Avoid heavy, fresh manures that can scorch roots, and avoid letting the soil swing from wet to dry. In containers, use a deep, rich mix with added compost and water‑holding material, and monitor moisture closely as pots dry faster than beds.

What are reliable tips for germinating celery seeds?

Use fresh seed, as viability declines with age. Sow on the surface or cover no deeper than 1–2 mm; light aids germination. Keep at a steady, mild temperature (around 18–21°C) and maintain consistent moisture without waterlogging—humidity domes help, but vent daily to prevent damping off. Germination can be slow and staggered, often 10–21 days. A brief pre‑soak can speed uptake, and bottom warmth encourages even sprouting. Once seedlings emerge, provide strong light, avoid drying out, and handle gently at pricking‑out time to protect the fine roots.

What is a practical celery spacing and care guide?

Set medium‑height celery with ample airflow: many growers space 20–30 cm between plants in rows 30–45 cm apart, adjusting to variety and local vigour. Keep growth steady—mulch and water evenly so the root zone never swings from drought to saturation. Feed little and often rather than in big bursts. Remove weeds early and avoid disturbing shallow roots. Self‑blanching types need minimal earthing up; traditional trenching types can be gradually mounded to pale the stems if desired. For companions, interplant with non‑competitive crops such as alliums and compact herbs, and avoid crowding with tall, thirsty neighbours.

How can I prevent celery from bolting?

Preventing premature flowering starts with timing: avoid cold shock by sowing early indoors but transplanting only after frost when soil is warming. Harden off gradually, protect young plants from prolonged chills, and keep growth even with steady moisture and nutrients. In hot spells, mulch and, if needed, provide light shade to reduce stress. Avoid letting plants dry out or sit waterlogged, both of which can trigger checks that lead to bolting. Choosing types noted for slow bolting and growing in the cooler part of the season in warmer climates also helps maintain leafy, succulent growth.

Guidance is summarised from standard horticultural practice and supplier specifications and is intended as a general overview. Conditions vary by microclimate, soil texture and fertility, drainage, exposure, and local frost patterns, so timings should be read via cues such as after last frost, when soil is workable, or, in mild climates, autumn sowing. Outcomes can differ with cultivar and cultural methods. Individual product pages carry specific instructions for preparation, spacing, and timing.

Cultivation notes and further reading

Apium graveolens seeds benefit from a steady, cool growing season and consistent moisture. Start indoors well before the last frost, as celery is a long-season crop that appreciates an early, sheltered start; transplant after the last frost when soil is workable and temperatures are settled. Sow on the surface or barely cover, since light aids germination, maintaining gentle warmth for sprouting, then cooler conditions for sturdy growth. Choose fertile, moisture-retentive soil with good drainage; mulch to keep roots cool and water regularly to avoid checks in growth. In mild climates, autumn sowing may be possible, while the main crop typically suits spring (Northern Hemisphere) / autumn (Southern Hemisphere). Blanching collars or closer spacing can produce paler, tender stalks, while wider spacing encourages more robust plants. Regular weeding and an even feeding schedule support uniform stalk development across the season. Further details on seed ranges, cultivation notes, and related species information are available at the link below.