TO START EARLY INDOORS
Start in early spring, 8-10 weeks before night temperatures are evenly above 50°F (10°C). Sow seeds thinly in containers of seed starting mix. Cover very lightly. Keep evenly moist; germination is uneven and takes up to 21 days. Keep seedlings at 70°F (21°C) range, providing a strong light source. Feed every 7-10 days with half strength liquid fertilizer like fish emulsion solution. When seedlings are well-established, plant in the garden 8 inches apart, so plants have room to grow and mature.
For growing success and optimum flavor and yield, growing celery plants must be kept consistently moist and well fed. Check often and water regularly; a thick mulch of compost helps maintain moisture. Fertilize every few weeks with a high nitrogen fertilizer or fish emulsion solution. Harvest outside stalks at maturity as needed or cut whole plant.