Why did Zhang plant buttonwood in Shuaifu? What's the story of this buttonwood tree? thank you

According to the old man, the phoenix tree can attract the phoenix, which means good luck and good luck. But I have been to Shuaifu myself. As far as Zhang's life is concerned, I think the biggest reason is decoration. The buttonwood tree near Shuaifu is really beautiful, harmonious and elegant, and Zhang is a clown. I don't think he has such a poetic idea to study what trees are planted in front of his house.