Forsythia are grown from cuttings. Select cuttings from new growth. Cut a three to six inch branch, and place the end into moist soil. Keep the soil moist to aid rooting. Rooting should only take a few weeks.
Water plants during extended dry periods as needed.
Fertilize plants once a year in early spring. Use a high phosphorous fertilizer to promote bright blooms.
Flowers form on prior year’s growth, not new growth. So, it’s important to prune them immediately after the flowers have bloomed.
You can cut back old growth to about four inches from the ground.
Forcing Forsythia to bloom indoors is a snap. Simply cut off a few branches, and bring them indoors. Put them in a vase with water. A couple weeks later, the branches will burst into bright cheerful, golden yellow blooms, right in the dead of winter