Q.pampas grass
Our pampas grass is now over 9 feet high. We love it but would like to leave the plumes alone while trimming back the leaves (blades?) to about 5 feet so we can view the backyard from our raised screen porch. Can we do this without harming the plant and plumes? Thanks so much!

Removing the leaves takes away the ability for the plant to feed itself.
Here is an article on controlling Pampas Grass.
https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/pampas-grass-removal.htm