Injecting some magic into the launch of Oxford in Bloom yesterday was Dumbledore from the Harry Potter films - actor and award-winning gardener Harry Robinson, right.

With colleagues from the Oxford in Bloom committee and the Oxford Mail, he was in gardening mode at the launch of this year's event in Cowley's Templars Square shopping centre.

Oxford in Bloom judge Trisha Stevens, left, said: "On the stall we had competitions for people to identify flowers with the prize as one of our hanging baskets as well as entry forms for the gardens competitions."

Event co-ordinator Mike Gass said: "There are 20 categories in the competition so everyone should be able to find at least one that their garden fits into.

"All we want if for people to put some effort into the gardens and make the city look a lot nicer."

Mr Robinson - who doubled for the late Richard Harris as the headteacher of Hogwarts in the films - is one of the judges in the competition.

He said: "We all have to make an effort and entering the Oxford in Bloom competition is a good way to get started."

The contest is open to everyone living within the city boundaries and the closing date for entries is July 11.