Pictures show that headstones are allowed, there's a post up thread that stated a headstone was on order. Has not yet arrived.
Flowers are brought to graveside for funeral - but afterwards they are removed. Some families take them home, divide amongst members. Some save the roses for rosaries to be made in memory of loved one. Some families will let the cemetery take care of them, which they will throw out. Some cemeteries will save just the roses for business's that make rosaries to have a supply on hand.
My opinion, maybe I'm alone in this view, but how one adorns a graveside is not a way to measure their love for the departed. When my loved ones passed, it was very hard for me to attend just the viewing, let alone to go back to the graveside and decorate it. To me, it was morbid to see a chunk of ground, freshly dug, mud, rocks, little to no grass and think, gee, I must do some gardening. My emotions were too raw (like the ground), and I know once there I will not hold it together. I'd rather leave their remains to rest, let the cemetery take care of the land, a headstone will mark the location and arrives later. When the sight is more in sync with the others, I can then go back and see the final resting place. Personally, I'd rather spend my time remembering and honoring in other ways.
In my family, visiting a graveside is very personal. No judgement of how often, or if flowers and trinkets are brought. Even though we live minutes away, it's neither looked down upon, nor praised for visitations. We know in our own heart of hearts what that person meant to us in the living world.