Thank you Urufu1997
I have started using the Grassland and Desert filters when using plants and foliage and that is how the plants all look so nice together. The park it is in started as Planet Zoo architecture entrance area using workshop blueprints - usually I prefer the tropical region plants and in game grass/terrain colours (they are brighter and more luxuriant - for I live in the semi-tropics of Australia) - then, for this park - I challenged myself with Desert Biome and 44 degrees Celsius most days - so I had to change from usual tropical foliage to Desert and Grassland plants so it looked right. I had never used the Planet Zoo architecture for buildings before this park - or so extensively - so owe the entrance inspiration to the Workshop brilliance of other players.
But - after the guests enter the entrance, the theming changes to African Desert and I stuck with it for the rest of the park. Hence the plant borders in the photos.
I have to say, the Desert and Grassland plants are AMAZING - and with the additions of the Australia Pack - the borders will look even better. I'm SUPER excited about the building pieces too - for the odd scatterings of decorative paraphernalia will be awesome.
Regards G