Maybe you can just divide your town into 4 different regions with different vegetation and PWP projects. The desert region with only a few dead trees and lemon trees near the river, and the Pyramid, Sphinx, and Stone Tablet.
An urban region near you town hall, few trees but a lot of bushes for hedges. Place your Police Station and Cafe in this area as well as Benches, Streetlights, a Clock, Fountain, maybe a park as well with a Jungle Gym, Sandbox, and Drinking Fountain.
A forest region with lots of pine trees and flowers. Your Campsite, a Fire Pit, Hammock, Log Bench, a Water Pump, and the Windmill would look good in that area.
A jungle region with trees and bamboo spread throughout. You can place a Geyser, Hot Spring, Rack of Rice, and the Zen Garden and Zen Bell in this area.