Fruit Trees and Spruce Trees

I had posted this question in another post, but never received a response to it. So, I am breaking it out into it's own post.

I am cutting down two blue spruce trees to make way for three apple trees. The spruces are about 40 years old and large with a big root system. All three apple trees will be situated in the root system of the old trees. So, knowing that spruce is allelopathic, how long will the roots continue to put off toxins? Will this kill the trees I want to plant?

Thanks for the input.

  Im curious what folks say to. One thing I know is a trees roots can stay alive and even grow for seven years after you cut it down. it depends on the tree i guess. People i knew as a kid had a trees roots messing with the walls in their basement. so they cut it down, but the problem got worse. turns out the roots were still alive and growing.

  Ive got fruit trees growing under other types of pines just fine but they arent spruce.

I’m guessing the allelopathic mechanism for spruce is not via a root exudate but leaf litter.  I also think there are very few plants that can increase root growth once the stem has been severed, especially a spruce tree.  I do know that fruit trees planted on a recently cut spruce have a tough time surviving.  It might be the high C:N ratio of the decaying root system.  Perhaps the best approach would be to add a lot of high N organic matter such as fresh manure for the first season after felling the spruce, then plant your apples the next growing season.

you might want to build up the area above the newly opened soil with some good soil from non evergreen woodsy areas??

Thanks for the replies.

I can't wait a year because I already have the trees coming. The idea of adding soil is a good one. How about a nurse plant?