The name Celeriac has to have been derived from the Latin word "celer" (quick). If so, it was a bad chioce. This vegetable takes ages to develop. I sowed the seeds for mine in early March, and I reckon that at the rate we're going, the veg might just be ready in November!
This is the third year in which I have grown Celeriac. The first year was more or less a complete failure. Last year I had a very small crop. This year I have gone to great lengths to do better. I have been giving my Celeriac a feed of general-purpose liquid plant food each week for about two months now, and I am watering the stuff with almost religious fervour - at least once a day, sometimes more often. I have read that the application of copious amounts of water is vital to success. You know how they force-feed geese to make foie gras? Well, imagine my Celeriac being urged to drink up more and more water...
Anyway, so far, so good. My six plants are looking healthy enough, and the bulbs are now about the size of a tennis ball. Not big enough! I'm hoping to get them to about the size of grapefruit before the cold weather sets in.
As the plants grow, the bases of the outer leaves split one by one and fall over. At this point you should remove the leaf, and any little side-shoots that appear, to keep the bulb reasonably smooth, and to allow light to reach it.
Anybody else out there growing Celeriac? If so, please let me know how yours is doing, and give me any advice you can on how to get good results!