I have a small backyard that backs up to a wooded area. The wooded area does not provide shade in the afternoon, as the lowest branches of the mature trees are probably 40 feet in the air. I would like to plant a flowering tree near the wooded area between two oak trees. These trees are 15-20 feet apart. Can I plant any flowering tree near these oaks without damaging the oaks or wasting my money on the flowering tree?