You will need to add a few things to the mix. Edit Pelleted /Edit Sulfur, Dolomite, Blood and Bone meal, ground leaves, and perlite. (maybe some sand for silica)
The horse poo is good (though it may contain seed from their feed that will still grow) and be hot. The wood chips will reduce N until they rot then release it to be used.
I make my own soil, look up my thread on growing trees for current pics. IF you get all the things needed your plant will luv you for it, and no need for expensive additives or flushing at the end..