What is its growth rate. How much length a 1.5 feet Alstonia attain in a year or two. I am planting some outside my house. I am preparing a square iron fence of 5 feet height for each tree. Can it reach upto 5 feet in a year. I have bought Conocarpus also. Nursery man told me its shady tree and very fast growing. I suspect Alstonia is slow growing tree?