Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Planting
Forsythia performs best in sites that provide well-drained soil and full to mostly sun.

To plant, dig a hole no deeper than the root ball and two to three times the width of the root ball and fill it with water. If the hole drains within a few hours, you have good drainage. If the water is still standing 12 hours later, improve the drainage in your bed, perhaps by establishing a raised bed. Turn and break up the soil removed from the planting hole. Mix some organic compost if the native soil is clay or compacted soil. Remove your plant from its container and carefully but firmly loosen the root ball. Set the plant into the hole you've prepared, making sure the top of the root ball is slightly above the soil level. Pull your backfill soil mixture around the root ball in the hole, tamping as you go to remove air pockets. Then water thoroughly and cover with a one to two-inch layer of mulch.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Pruning
Forsythia does not require pruning however, if you want to control the size or shape of the plant, you can prune them immediately after they have finished blooming in spring. Forsythia respond well to pruning so you can cut them as far back as desired.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Feeding
I fertilize forsythia one time a year with a well-balanced shrub & tree type fertilizer after they've bloomed in spring.

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F · Comment About Problems
I've seen no serious insect or disease problems with forsythia. These are quite tough, long-lived shrubs. Consistently wet soil could cause problems with the roots.