Celery question

[greengas]

I am growing celery giant pascal but have not dug a trench, I have put them in a bed which I was going to build up with compost around the celery. My question when do I earth up and do I have to tie at top and put carboard round first? I am confused as different books say different things. I think I have alraedy made a mistake by not digging trench

[rustylady]

Link here - dunno if it will help Quality Vegetable Seeds through Suttons Seeds - Suttons Seeds and Plants

[greengas]

thank you rustylady I will take a peak now!