Phineas gage suffered a serious brain injury when a rod went through his brain. the importance of his injury to psychology was

 the importance of his injury to psychology was The interest in the brain that his injuries caused
His case was extremely unique because he was the first recorded man ever that had a solid object pierced through his head and still managed to survive. His case has improved Medical knowledge about Human's brain anatomy.

Water them on a regular basis, make sure they're getting sunlight, and chopping off any dead/dying branches that can infect the rest of the tree.