Ilona

Celeriac

Zone 9b Save Garden

🌱 105d to harvest Rosette

Silky, aromatic flesh with a crisp, pearly snap—Ilona celeriac forms a handsome, globe-leaning bulb crowned with fresh green—its …

Crop Dates

Milestone	Date
Start Indoors	Dec 1st
Last Frost	Feb 9th
Transplant / Sow Outdoors	Feb 2nd
Harvest Begins	May 18th
Harvest Ends	Dec 9th

Crop Details

Trait	Value
Days to Maturity	105
Sun Requirements	Part Sun
Growth Habit	Rosette
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	45
Min Night Temp (°F)	35
Harden Off (days)	7

Recommended Companions

Frequently Asked Questions

What pest or disease commonly affects celeriac (Apium graveolens var. rapaceum), and what should I do if I see it?

Celeriac commonly suffers from celery leaf spot/early blight-type leaf spotting (dark, irregular spots on leaves) and can develop fungal issues in wet conditions. Remove the worst affected leaves, improve airflow by spacing plants and watering at the soil line, and avoid overhead watering. If spots spread quickly, start a labeled fungicide for celery/Apiaceae and apply according to the label at the first signs of leaf spotting.

How often should I water celeriac during the main growing phase, and what soil moisture target should I keep?

During the bulk growth period (roughly mid-season until bulbing begins), keep soil consistently moist but not waterlogged—aim for a damp “wrung-out” feel in the top few inches. Water deeply about 1–2 times per week depending on heat, and increase frequency during dry spells so celeriac doesn’t dry out and crack or become woody. Mulch helps stabilize moisture, but never let the crown sit in standing water.

How can I tell when celeriac (Apium graveolens var. rapaceum) is ready to harvest?

Harvest when the tuberous root is well-developed and about the size you want (often softball to larger), typically around 105 days from sowing/establishment. The best indicator is size and firmness: the bulb should feel solid with smooth skin, and the outer roots/leaves may start to yellow as it nears maturity. If frost is expected, plan to harvest before hard freezes for best texture and flavor.

Silky, aromatic flesh with a crisp, pearly snap—Ilona celeriac forms a handsome, globe-leaning bulb crowned with fresh green—its flavor both mellow and deeply celery-sweet. The texture stays tender and fine-grained, making it a standout for roasting until caramel-kissed, for velvety purées and soups, and for bright, tangy preparations where its distinctive celery character shines. Grow Ilona for a dependable 105-day season and a harvest that looks as refined as it tastes.

Sowing Tips

Transplant Conditions

Wait until soil reaches 45°F and nights stay above 35°F before moving outdoors. Harden off for 7 days first.

Expert Note

Start celeriac early for a long root-building season, then transplant into evenly moist, heavy-friendly soil and keep the base of the stem above the root surface as it fattens.