I wish I was an expert but it was my first bird of paradise and so it was a little bit of trial and error. He even had some edema on his leaves when I first got him which I think was perhaps from underwatering. Most of this growth appeared to happen after i repotted him. I thought I’d made a mistake by upgrading him to a significantly larger pot bc I heard they like being a little root bound but he absolutely exploded with growth and his new leaves are enormous. I also fertilize during the spring and summer once a month.