Depending on the variety, they can reach anywhere from 4 feet tall to well over 6 feet for some heriloom's. It seems a little late (by our U.S. standards) for no blooms to have appeared by now. I'd suggest keeping them well watered and adding just a little (maybe a teaspoonful per plant) of a good high nitrogen fertilizer. If you only started the plants from seeds say, in April or May, that may be your problem. Here, we start them in March or even late February and they are nearly a foot high by the time they are transplanted in mid to late May. Keep them watered and they should come around... Best of luck!