Forsythias are a genus of deciduous flowering shrubs that belong to the olive family. These low-maintenance, fast-growing shrubs feature an upright, arching form. They are known for their long branches that fill with brilliant yellow blooms early in the spring. Forsythia flowers precede their leaves, which means you get a good look at the blooms with no foliage to block your view.Bees and butterflies love forsythia, and they provide a cheerful backdrop, border, or centerpiece for any yard. Some smaller forsythia varieties only stand a couple feet tall with a slightly wider spread while many of the larger varieties can reach around 10 feet in height and spread.