suspensa) and greenstem forsythia (F. viridissima), with traits that are "intermediate" between the two parents. Some of the most common forsythias include: Prune forsythias if you want to ...

While forsythia plants, for the most part, are hardy to zone 4 or 5, the flower buds may not be as hardy. When temperatures drop below minus 10 degrees Fahrenheit, flower buds may be killed or ...