Question
i live in Scotland and was wondering if you could tell me if it is possible to transplant a 30 year old magnolia tree? if it is when is the best time to do so and how would you do this?

Answer
Deciduous may be planted either in the spring or the fall. Deciduous plants may be moved in the spring as soon as the frost is out of the ground, up until the time when new foliage is partly unfurled. In the fall, they may be planted once the leaves start to turn color up until the ground freezes.

When you want to dig up a tree or shrub for transplanting, retain as much of the root system as possible. Older deciduous trees can be successfully moved only if a ball of soil is left around the roots. The exposed roots should be protected with moist burlap or newspaper or with polyethylene sheeting. Every effort should be made to reduce root exposure to wind and sun, keeping the ball as moist as possible. It's best to prepare the hole before digging up the tree you wish to move.

Size of the root ball and size of the hole:

For deciduous trees and shrubs the soil ball should be:

Width = 9-12 in. in diameter/every 1 in. of tree diameter
Depth = 6 in./every 1 in. of tree diameter

For example: A tree trunk 2 inches wide would need a soil ball of 18-24 inches wide and 12 inches deep.

This root ball will weigh a great deal and really need a professional with a tree spade to move it. Here in the US there are dealers of a tree spade called Vermeer I do not know if these are in your location.
The new hole needs to be twice the size of the root ball and as deep.