I have just recently aquired a monkey puzzle tree that has been kept in a pot, unfortunately I think the tree has been too long in the pot as the lower branches are quite brown. I have replanted the tree in the ground now and am giving it general plant feed to try to revitalise it, does anybody have any suggestions that may help?
You have likely lost those lower branches, but don't despair! Since you've got it in ground it will produce new ones at the top, and eventually it will develop into an attractive tree. The more water you can give it, the better - that way the growth will be more compact and less spindly. Beware, also, of overfeeding it - once a week should be plenty for a young plant. Other than this, wait for all traces of green to leave the lower branches, and gently remove them with a small saw or loppers (depending on the size of the tree) close to the main trunk. If it really is a Monkey Puzzle, you'll want to wear leather gloves to do this, as the dry foliage is quite sharp. If it's a Norfolk Pine, which is also sometimes referred to by the same name, you can do this bare-handed with reasonable safety. Hull, Quebec, or Hull, UK?
The major problem is going to be coiled roots from being too long in the pot. Did you try to uncoil them at all before planting? If no, there's a high risk of the tree becoming unstable when it gets larger in 10-20 years or so.