Forsythia Pruning

Forsythia pruning is simple. Perhaps too simple, as many people shear their plants into unnatural shapes rather than prune them to promote healthy growth. Forsythia plants are early bloomers that have a natural vase-like or weeping habit-proper pruning maintains this shape.

Pruning Forsythia Correctly

Forsythia plants are a fast growing, cane-type species whose blooms are often provide the first burst of color in spring. The blooms precede the growth of leaves and only occur on growth last year's growth. Although many people try to shear or force forsythia into geometric shapes, the preferred method of pruning involves promoting the natural shape of the plant while creating better light penetration and air circulation. Here's how to get started:

• Start out right. A mature forsythia can grow to 10' tall and wide. By planting forsythia in a location that will allow it to reach its ultimate size, you remove the need for drastic pruning. That little twig you brought home from the nursery will become a mighty shrub-plan for it.
• Pruning on time. The best time for pruning forsythia is just after the peak bloom time, typically in early to mid spring, depending on your climate zone. Pruning too early will result in little or no bloom production this year, while pruning late can impact the following year's blooms.
• Tool time. Use sharp by-pass pruning shears to cut your forsythia canes. Larger canes may need to be cut with pruning loppers or a pruning saw. Sanitize the blades of your tools with alcohol or with a water and bleach solution (4 parts water to 1 part bleach) prior to pruning each forsythia plant.
• Make way for new growth. Begin pruning forsythia by removing 1/3 of the oldest, tallest canes, cutting them off at ground level. This thinning of your forsythia will automatically reduce its size and provide room for new growth.
• Cleaning house. Next, remove any dead, damaged or diseased canes. Also, remove any canes that are rubbing against one another or growing back toward the center of the plant. Finally, cut back any canes that are touching the ground, as forsythia plants have the ability to "tip root" and create new plants for growth that contacts the ground.
• Reboot. Take heart if your forsythia has gotten so out of control you don't know where to start. To rejuvenate overgrown forsythia, cut the entire plant back to the ground in late winter-in less than a year, the plant will produce new canes and begin the cycle of life again.