Forsythia (Forsythia x intermedia) is a non-native, deciduous, woody ornamental shrub. It provides only little wildlife benefit, but it is good for soil retention and a privacy barrier and is a fast grower.
It is an early spring bloomer and provides bright yellow color to the landscape when there isn’t much other color. Flowers are profuse and bell-shaped, appearing in March through April before the leaves begin to grow. Flowers form on the previous year’s new growth.
There are several cultivars of Forsythia and they vary in size of the flower, size of the shrub, and growth habit (erect or weeping). Forsythia intermedia is the most common type in the Southeast.
If you don’t mind the natural look of the shrub (stems will protrude in every direction), there is no need to trim it back. However, if you want to shape the shrub, trim the old branches back just after the plant has finished flowering.
How to grow Forsythia
For the showiest blooms, plant Forsythia in full sun in well-drained soil though it can tolerate a variety of soil types. It can be grown in zones 4-8 and will grow as tall as 10 feet and equally as wide.
Forsythia can be rooted from softwood cuttings. Here is a quick guide on taking and growing cuttings: http://www.bhg.com/gardening/yard/garden-care/starting-flowers-from-cutting/
Since it is from Asia, native wildlife does not make much use of Forsythia. I have seen some reports of bees getting nectar from the flowers, while others claim the bees ignore their shrubs. (example: http://www.beesource.com/forums/showthread.php?248055-Forsythia). I have not noticed any bee activity around the shrub in my garden.
The shrub is deer-resistant and perhaps its best wildlife use is for cover for birds and rodents. Every time I go near the one bush in my yard, a bird or two scurries out from underneath it.
I also came across a report from the Georgia Department of Natural Resources that states that house finches eat the buds and blossoms of Forsythia.
Note: There is another yellow-blooming shrub that could be confused with Forsythia: winter jasmine. The difference is this is not a woody shrub, the stems are green, and the flowers are much smaller. Also, the jasmine begins to flower before the Forsythia (as early as November).
Learn more about Forsythia here: http://www.clemson.edu/extension/hgic/plants/landscape/shrubs/hgic1064.html