Florimart

Celery is especially prone to celery leaf spot (fungal spots on leaves) and can also suffer from aphids, which cluster on tender shoots. Remove and discard heavily spotted leaves, avoid wetting the foliage when watering, and improve airflow around plants; if leaf spot is recurring, use a labeled fungicide appropriate for edible leafy vegetables. For aphids, spray plants with a strong jet of water and repeat every 2–3 days until colonies shrink, or use an insecticidal soap labeled for celery.

Harvest when stalks are firm and reach a usable size for your preference, typically around the 85-day mark from transplanting (or roughly late-season if grown from seed). The stalks should be crisp with good color, and the plant should feel solid at the base—if stalks pull away easily or look hollow and stringy, wait a bit longer. For best flavor, cut outer stalks first and let the center continue growing for several days if your plants are still filling out.