Just a bit of a warning.
RHS Wisley has a lovely model vegetable garden, with raised beds and little gates leading in (to keep out rabbits etc). If you enter it from the rock garden area, you come in at the shed end and there's no indication of any problems.
If you enter from the orchard side, there is a board telling visitors that club root is endemic in the garden, and how they minimise the effects.
I walked into it from the unmarked side, wearing my gardening boots! And was very cross when I found out about the club root. I got back to the car, took off the boots and put them in a plastic bag and drove barefoot back home, scrubbed the earth off the boots and put them in Jeyes fluid for a few hours. They smelled for weeks!
So beware, if you're visiting Wisley, don't wear any shoes that you'll wear at the allotments if you don't already have club root... as it can be transferred on shoes. Bear in mind that even if you don't go in the veg garden, others have done, and have probably walked it out onto the rest of Wisley too.
moonbells