I have some areas on my layout where the older ground foam is looking a little “tired”. Is there a way that I can rejuvenate it to give it a fresher look or is the only way to go back over it with some new ground foam and scenery materials.
Try lightly spraying with some plain water. That will often brighten things up considrably. Many scenery products are subject to UV induced fade over time however, and with those the only option is to add new material.
If vacuuming doesn’t still freshen it up and you only need to doctor up some colors to brighten, spraying w/ unscented hairspay (pump) and sprinkling on fine grasses and ground foams will work. I find the hairspray best for trees and foliage. The ground covers themselves may need to be set using scenery glue/ matte medium for a bit better hold.
Bear, your response about the spray can reminded me of a method used by Joe Fugate. A dusting of yellow and/ or sprinkling of yellow grasses on the tree tops works to show sunlight/ highlights upon the forest canopy. Adds a great illusion of more depth. Just need to go easy, highlight the taller as if catching morer sunlight.