How to Grow Forsythia for Spring Color
When I was a child in the chilly climate of upstate New York, I never understood my mother’s fascination with forsythia. To me they were just scraggly bushes with a few pathetic flowers in the early spring. As an adult, I moved to the warmer climate of New Jersey and finally understood my mother’s love affair with the golden harbingers of spring. Here in NJ, they are huge, sometimes invasive and in early spring are covered with bright yellow flowers that proclaim that spring is finally on its way.
What are Forsythia?
The forsythia is a deciduous shrub that is related to the olive tree. It was named for William Forsyth, a Scottish botanist who was one of the founding members of the Royal Horticultural Society. The shrubs are native to Eastern Asia. They were introduced first in Holland in 1833 and then in England by the 1850’s.
Forsythia bloom in early spring when the soil reaches 55⁰F. The blossoms appear before the foliage. Once they finish blooming, the flowers drop off and are replaced by green foliage which turns burgundy in the fall. Forsythia are grown for their flowers. They can be used as specimen plants or for hedges and boundary markings.
How to Grow a Forsythia
Forsythia are hardy in zones 5 through 8. They need full sun and well-drained soil. Most gardeners plant their forsythia in the spring because that is when the nurseries are offering them for sale. It is also conveniently after the shrubs have bloomed and everyone has seen them and now wants to have them in their yards. It is better though to plant them in the fall so that the roots have a chance to become established before the bushes go dormant at the end of October. Then in the spring, you will be rewarded with flowers.
Most forsythias are sold in containers. You may also see them sold as “ball and burlap” where the root ball is covered with burlap. Whether you are planting in the spring or the fall, the procedure for both is the same. Choose a sunny spot with lots of space. These shrubs can grow up to ten feet high. If you are installing them for a hedge, plant the shrubs 4 to 6 feet apart. Remove the shrub from its container and dig a hole that is as deep as the container or burlap ball and twice as wide. Place the shrub in the hole making sure that the top of the hole is the same height as the top of the root ball. Fill in the hole around the root ball and water thoroughly. Install a thick (2 to 3 inches) layer of mulch around your shrub making sure that it doesn’t actually touch the stems. The mulch will prevent weeds from growing and help keep the soil moist.
Provide your shrub with 1 inch or more of water each week during the growing season. You do not need to fertilize the bush in the first year of growth. After that, you can fertilize once a year in the spring after the shrub has finished blooming with regular balanced fertilizer (10-10-10).
How to Prune a Forsythia
Forsythia don’t need to be pruned every year. In fact, when they are planted as a hedge, you want them to grow and spread. Left alone for too many years, they can get out of control so you will want to prune them every few years. It’s important that you wait until after they have finished flowering before you prune. If you prune them in the fall or winter, you will be pruning off the flowers because forsythia blooms on “old wood” which means that the flower buds develop during the summer, then go dormant until the early spring when they bloom. Plants that bloom on “new wood” usually bloom in the summer or fall because the buds develop on the current year’s growth or branches rather than the prior year’s growth.
When you prune, you will want to remove ¼ to ⅓ of the oldest stems. This will stimulate the bush to grow new, healthy stems. Removing old stems keeps the shrubs vigorous and prevents the larger, older stems from bending down to the ground where they will take root to make new shrubs. After removing the old stems, you can prune the shrubs to your desired shape.
How to Propagate Forsythia
Forsythia are very easy to propagate. In fact, if you don’t prune the oldest stems, they will propagate themselves! The technique is known as “layering”. You bend a branch down to the ground (or a stem bends to the ground through its own weight), anchor it and cover with some soil leaving the end of the branch with some leaves on it exposed. In 4 to 6 weeks, the branch will develop roots. You then sever it from the parent bush and plant it elsewhere in your garden.
You can also propagate forsythia through cuttings. You will want to take your cuttings in the spring after your shrub has finished blooming and the branches are starting to leaf out. Take your cutting from young, actively growing branches. They will be pliable and easily bent. Cut off 4 to 6 inches of each branch that you want to use. Dip the cuttings in rooting hormone and then plant them in pots in indirect sunlight and keep them evenly moist. Some gardeners cover the pots with plastic to keep the cuttings humid, but it’s not necessary. Roots should begin to grow in 4 to 6 weeks. Keep your saplings in a sheltered area during the summer and then plant them in your garden in the fall or the following spring.
If you don’t want to go to all the trouble of plastic covers and sheltered areas, simply make your cuttings, dip them in rooting hormone and then just stick them in the ground! Keep them well-watered and they should develop roots in 4 to 6 weeks. When you see the sapling start to put out new leaves, you will know that roots have begun to grow.
© 2018 Caren White