Pink Plume

Celery is prone to early blight–type leaf spot and, in damp weather, septoria leaf spot, which show as dark spots that expand and yellow surrounding tissue. Keep leaves dry by watering at the soil line, space plants so air can circulate, remove badly spotted leaves, and use a preventative copper-based fungicide labeled for celery if spots start. If you see slugs or celery leafminers, use hand removal at dusk and trap/physical barriers around stems while continuing sanitation of fallen debris.

Harvest at about 90 days from sowing when stalks are thick enough to stand up and feel firm rather than floppy. Look for stalks that have blanched to a light pink-to-pale color along the ribs (stages vary by how you blanch), and ensure the plants reach a usable size with tops not yet starting to bolt. For best quality, harvest in the cool morning and avoid leaving cut stalks exposed to sun for long.