The Great British gardener's quiz - how green fingered are you?

I just tried answering a  few practice UK citizenship tests. Just out of curiosity, since I’m allowed to be here already, but in any case they didn’t seem all that difficult. My favourite question was “John Constable (1776-1837) founded the modern police force in England. True or false?” 

But what slightly puzzled me was the complete absence of questions about something that I suspect is central to the character of many Britons: gardening. So I decided to have a go at rectifying the omission.  In keeping with the spirit of the genuine test (“King Henry VIII’s daughter Mary famously persecuted Protestants, and thus became known as Scary Mary. True or false?”), some of the wrong answers are not all that plausible.