Veggie Punnet Celery - Allium graveolens Celery is a crispy green vegetable which produces edible stalks continuously over several months. Growing Tip: This celery is self blanching but apply liberal amounts of fertiliser and keep well watered in the growing season for a robust, healthy plant. Position: Full sun Height / Spacing: 30cm apart, in rows 40-50cm apart. Lifespan: Annual Planting Time: Spring, Summer (Sept-Dec) Harvest: 16 weeks from early plantings; 20 weeks from late plantings.