Celery is best for locations with longer cool seasons with a good amount of moisture. This will give you the best result. You should start transplanting them about 2-3 weeks before the last frost. They can hold up under a light frost but too much heat will cause problems. If you have a spot that is mostly shaded in the afternoon, that would be best, this will protect the new plants from the afternoon sun and heat. You will need a good compost. Spread about 2 inches over the garden bed. Make sure that the spot where you plant holds moisture and does not get soggy. Mix the compost into the soil to a good depth. This will give it nutrients and help it hold water. Plant them about 8-10 inches apart and water them often ensuring that the soil does not become soggy.