Posted: 16/04/2014 at 11:29
If your tree is that old it will be fine. My neighbour digs over underneath her apple and pear tree. The roots of the tree will be quite deep, it will obviously have surface roots too but it won't harm the tree if you plant whatever you like underneath even grass, it will be totally fine. I've got bulbs and Monkshood underneath mine, oh, and an old rose. Some people freak out about Monkshood but it's complete nonsense it won't harm the tree to any extent that you'll notice.