I love what you have done so far, but I, like the others, think it needs a border. A border frames the "art" and makes it stand out. I would start with a dark color first, maybe a 1-1/2" dark green. Adding another border will depend on how much you want to add in size. A 4-5" second border will give it the finished look. This is all just my honest opinion of course. It is your quilt and you need to do what you feel is best for you!