These can purchased at most GC. Statue but a little later on in the season and then mostly in plant form. If you google canna bulbs there are loads on offer.

I've recently discovered from seasoned Canna growers that they can be bought to bloom in a single season from seed.
Now is the time to start, and Chiltern Seeds have a fair range of the Canna species and some hybrids.

Have a look on Ebay this seller has some good ones
http://www.ebay.co.uk/itm/260947592452?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

thanksa lot for all your help