Personally I do think it would clash with the natural vibes too much, especially considering the inspiration pics you shared months ago, but only you can judge the practical pros and cons! I never did landscape design besides tiny rock gardens so the following will be the point of view of a complete amateur, and of course entirely subjective, so please take it with a grain of salt. :) That said – I think pampas grass sounds awesome if it was in smaller area, placed somewhere where it wouldn't cover your view of the water. Taller ornamental grasses seem to easily take over the landscape so the placement would really matter imo. (source) The smaller rocks that were visible on the side when you added manzanita (and if I'm not mistaken, you added more of them after planting the trees?) really helped a sort of natural transition between the water and grass, that's lovely! Looks a lot more natural to me. The rocky hill above the waterfall (on the right of the little seating area) looks like it'd be great with some low, dense, colorful plants/herbs so you'd get a variety of colors and "textures" breaking up the rocky surface? I don't know which plants would work with the climate and be low-maintenance, but I do think small pops of color with something bright like thyme or aubretia and then some neutral greenery and grasses around it could look great. (The photos below are more decorative and colorful than what I'm imagining.) (source 1, source 2) You might even do a "wilder" section (with your trees, tall grasses etc. which would probably require less upkeep) transitioning into a rock garden on the side? Or keep some herbs in the more accessible area. I hope you'll keep updating us as the plants grow, because it already looks so lovely!!

"Our helpful contractor has offered to pour curbing 3' from the fence around the yard, but it will probably be straight. I'm trying to decide if that's best." As a professional landscape designer, I think this is a very poor design decision. First, a 3 foot width is barely wide enough to support most perennials, let alone any shrubs that would give the garden some structure and year round presence.. Second, concrete curbing is a far too permanent or hard to remove solution to keeping the lawn out of the planting beds. It takes very little effort to manually edge the beds a couple times a season or you could opt for an easy but less permanent solution and use flexible edging (available at most home improvement stores) or stone or concrete cobbles intended for this purpose. And finally, straight, matching parallel borders are best in a more formal setting, whereas graceful and generously sweeping curves lend themselves to a more natural, casual style.

When I ran a small town parks department, we would order two kinds of mulch, landscaping and playground. Playground mulch is different in that it's cut/chipped different to lay different and not have the pokey bits or big lumpy bits that many landscaping mulches can have. We did have retaining rails around playground areas to help keep the mulch in that area. Three of the parks had playgrounds, including a little childrens park. Each park took a truckoad or two to refresh every 3-4 years. This depended a bit on traffic. The least used park was fine with a truckload every four years, the childrens park tended to need 1-2 loads every three years, and the biggest and most used one needed a couple truckloads every three years. Sometimes it could be put off till the spring of the next year after the next town budget got approved. I never tested the mulch myself, just observed lots of kids using the equipment and working with my guy on replenishment schedules for various things. Depending on the age of your kids, you might only want mulch for a few years. I can understand if you have little ones. But by the time they are hitting double digit age they are pretty sturdy without needing mulch so much. Just observations again, but older kids fall down a lot less than little ones. Another alternative if you can is do a deep sand court. Some places have groomed volleyball courts of deep soft sand. That is also a kid friendly outdoor surface. It's water free. Might be cheaper than wood mulch out in Vegas.

My house is south facing and I’m in a northern suburb of Illinois. I am thinking around $800-$1000. For me an oasis has beautiful plants, a nice conversation area and a place I could curl up and read a good book!