There are plenty of red hydrangeas in Europe, but USA doesn’t really have the climate for this color in hydrangeas. It didn’t come close, until Summer Crush, whose rich raspberry red hues are the nearest to true red that any hydrangea has ever been in US soil. It’s on a gorgeous, impressively heat–tolerant plant, too. Rich green, serrated foliage fills out a compact habit. It is extremely bud hardy, so it will reliably bloom on both old and new wood.
The wealth of flowers will bring on the butterflies. Also, as a macrophylla, it changes colors depending on the pH balance of the soil, but not to the typical blue. If your soil is more acidic, with a good aluminum availability, it will flower in rich purple.