And no, I don't mean 'walk out to the nearest forest and cut one down'

Does anyone know a place in the south east (preferably closer to the M25) where the public can go, choose their own xmas tree and either dig it up or cut it down? (Directions if possible!)

I have spoken to people who say this is a great way of getting a fresh, great-looking tree at a cost cheaper than most DIY stores or garden centres, but for love nor money have no idea how to go about finding one (apart from spending days driving around in the car hoping to stumble across one!)

Being an avid DIYer this is a great idea!