Tetragold Forsythia. We got Tetragold Forsythia years ago, and it is a large and vigorous grower. The main attraction for this cultivar is that it doesn't get root rot problems like many others have with us. We are probably on the most southern range of where Forsythias perform well, and I think our warm soils induce more root problems. The flowers are large, abundant and showy. The fall color can be almost as yellow as the blooms.