At our annual gathering several people asked about Celeriac. Sue’s advise is it is a bit of a tricky vegetable, but with a rich soil (lots of compost), and constant moisture (so water every day and keep the plants damp). In addition, as it grows, pull off the outer leaves to reveals the ‘bulb’ as it swells, and it should do well.
Some garden books say it is easier than celery (not our experience). Lesley says she successfully grows celeriac but after a vole invasion last year in which all her beautiful celeriac bulbs were eaten by the critturs, she is growing them this year in old animal feed containers, and they look wonderful. (They will be netted soon in case the voles find a way to jump into the containers!!)