I'd be tempted to build a wooden deck around the pool. Those rocks would be killer on bare feet! Decks look great with lounge chairs, and a chest to hold pool toys. My zone is much hotter than yours, so not sure what grows in your area. I'd choose plants that don't shed. Nothing worse than a lot of leaves in the pool. Don't pick plants that attract bees. We have sago palms, society garlic, a couple low shrubs, and pine trees. The pines are a good distance from the pool, so they don't drop their cones or needles anywhere near the pool. Good luck!

I have a very tall podocarpus gracilior hedge around our pool on three sides which I affectionately refer to Hedgezilla. Yes, it can get big, but to keep it under control in a small, tight suburban setting as ours is, it becomes a maintenance nightmare which I've delegated to a very expensive tree-trimming company. Yes, this plant doesn't break or lift concrete or create oodles of litter, doesn't have thorns and is disease- and pest-free, and never needs water once established. (Ours has been in since the early 90s.) But, it's boring. Boring. BORING. Worst of all, it doesn't provide any wildlife benefits or visual interest. I hate it. It's the bane of my existence. I've decided to gradually replace it with a selection of plants that will be more natural looking, provide some wildlife benefits, and won't require a heavy-handed, man-made intervention on a regular basis.

I had a similar problem. I removed the fence around my pool when I had the deck redone. I wanted a privacy screen close in so I used a combination of things. I made 5 trellises from 4X8 vinyl lattice and put them on landscape timbers about 2 feet above the ground and kind of framed them. Basically this made an 8 ft wide trellis with the top about 6 ft high. On two of these, i put Lady Banskia roses..they are evergreen. One one I am growing Confederate Jasmie and one one Carolina Jasmine (which isn't as thick a screeen as the confederate). The 5th trellis has another climbing rose but isn't really a good screen. I sort of placed these trellises at intervals around the deck toward the corners but not exactly symetrically.. In between these are a variey of other plants, viburnum which makes a bigger lush tree and lorepeltum for it's rich red coloration. The bed around my deck is of varying width from maybe five feet at the back of the pool to 10 feet on one end. So I also have room for compacta and some other hollies as well as day lillies, a few sago palms etc.. I used this other stuff for a low to the ground screen but also to give some texture /color differences. I've been shaping these other plants, some round, some square etc.. I'm definitely not a gardening artist, I just like to play and add stuff, but the effect is nice.

If that's the case, look at the first and second picture again and ask "what value are they?" They make it look as if there is 6" to 12" between pool deck and fence!!! Leylands are for when someone needs massive height. (They have their downside.) Is great height what you need? Arbs would be a better choice for common height. Other things good for even less height.