Placing flowers on a grave is not a Jewish tradition. Why not? Here’s a thought:
While flowers are a beautiful gift to the living, they mean nothing to the dead. In death, the body which is ephemeral and temporary is gone, and all that remains is that eternal part of the person, their soul. The body, like a flower, blossoms and then fades away, but the soul, like a solid stone, lives on forever.
In the world of truth, the place we all go to after life on earth, what counts is the lasting impact we had on the world. It is the achievements of the soul, not of the body, that remain beyond the grave. The money we make, the holidays we go on, the food we eat and the games we play – these are all flowers that die along with us. But the good deeds we do, the love we show to others, the light we bring into the world, these are eternal.
If you want to honor your loved one, take the money you would have spent on flowers and give it to charity in their memory. Then take a modest stone that costs you nothing and place it on their grave, to tell them that though she is gone, the impact they had on you is everlasting.