Hi, I am new to pond keeping. Two years ago, we moved into a home with a pond. We've decided to keep the pond (that was up in the air for a while) and improve it. The pond contains a pair of koi, a few of their fry, lots of shubunkin, and many goldfish babies. We want to remove the goldfish (plans are in the works) and just have koi. There are a few potted lilies, umbrella palms, and rice grass plants. I am going to add more lilies, rice grass, some four-leaf clovers, and watercress. I collected some plants yesterday from some other koi ponds (with permission) and am wondering if I could just plant them in the gravel substrate instead of pots. Seems like it's just a don't not to pot your plants, but not exactly sure why.