Try rearranging the blocks. I love the colors (especially the greens) that you have chosen but they don't seem to be balanced as you have them. The suggestion of looking at it on point has merit, too. There's something about the on point arrangement that changes a quilt. I am a star person and these are so pretty and very nicely done. As to a border, this probably doesn't "need" one but I prefer a border to reduce handling/stress on the pieced blocks in time to come.