Combine the rose, pomegranate juice, lemon juice, sugar, Grand Marnier, Cognac, 1 cup of water, and 1 cup of ice in a large glass pitcher. Stir in the raspberries, strawberries, and plums, cover, and refrigerate for at least 2 hours but preferably overnight.
When ready to serve, fill wine goblets or highball glasses halfway with ice. Pour the sangria over the ice, spooning some of the macerated fruit into each glass. Serve ice cold.
Originally published as Summer Rose Sangria in "Make it Ahead" by Ina Garten © Clarkson Potter 2014. Provided courtesy of Ina Garten.