Celeriac

Celeriac (Apium graveolens) wants the longest season of any vegetable — it is started indoors as early as February and not harvested until October. The seeds need light to germinate: sow them on the surface and don't cover them with soil. Plant shallow so the crown stays above ground, otherwise the root won't swell. It needs constant moisture and rich soil all season long. In late summer, pull the soil away from the roots so they can mature. Harvested roots keep in the cellar all winter — the backbone of many a soup.