Not a veg. I've tried to grow... good luck!

Needs to be grown in a trench and needs plenty of water. Some varieties are self-blanching or you need to wrap the mature stems with corrugated cardboard to blanch. Supposed to be at its best when frosted in the winter.

hey thats usefull thanks Moon Growe and Jimmy I will dig my trench today when should I plant out my young siblings I have 8

Have a look at the BBC Gardening site for growing celery which has an indepth article including when to plant out.