I created and presented a Walled Garden project to my classes in 2000 and then again to a new group in 2009. It has now been replicated again, but this time in 1/24th & 1/48th scales. The kit is sold in bare uncoloured wood and will require constructing and colouring. 
 
The photograph shows the garden after all the instructions have been completed, allowing you to fill the greenhouse and plant out the raised beds as you wish.