Kelp/Aquatic Plants Manual Growth

I was messing around with a kelp farm idea today and I wanted to see if it would work by itself, so I tried to use bonemeal on the kelp to get it to grow, but discovered that was not possible. I was thinking that maybe a way to aid the growth of aquatic plants like kelp or sea pickles would be a neat thing. Maybe using bonemeal on a sea pickle could add another pickle to the group. Just something I thought I might add here since it's relevant to what I was working on in MC today.