Forsythia is a popular, deciduous shrub known for its vibrant display of bright yellow blossoms that signal the arrival of spring. Its fast-growing, arching stems create an attractive, fountain-like shape. Correct initial spacing is a determining factor for maximizing the shrub’s spectacular bloom and maintaining its long-term health and natural form. Planting forsythia at the appropriate distance prevents overcrowding, ensuring good air circulation and adequate light exposure for optimal flowering.
Understanding Mature Size and Cultivars
The distance required between forsythia plants depends entirely on the specific cultivar chosen and its mature spread. Standard varieties, such as Forsythia x intermedia ‘Lynwood Variety’ or ‘Meadowlark’, typically reach an impressive mature spread of 8 to 10 feet wide if left unpruned. These larger shrubs have a vigorous, arching growth habit, meaning their required spacing is substantial.
However, many dwarf or compact cultivars are available for smaller spaces, dramatically changing the necessary planting distance. Varieties like ‘Gold Tide’ (‘Courtasol’) have a low-growing habit, maturing to only about 1.5 to 3 feet tall and wide. ‘Show Off Sugar Baby’ is a miniature variety with a spread of only 2 to 3 feet. Understanding the cultivar’s specific mature dimensions is the first step in determining the correct spacing, as all measurements should be based on the shrub’s ultimate size.
Spacing Requirements for Specimen Planting
When the goal is to showcase the forsythia’s natural, graceful, and arching form as a stand-alone display, or specimen planting, the shrubs must be spaced widely. For large, standard cultivars expected to reach an 8 to 10-foot spread, the ideal planting distance is between 8 and 10 feet apart, measuring from the center of one plant to the center of the next. This spacing allows the shrub to grow into its full, unconstrained silhouette without competing with its neighbor.
Providing ample space ensures that the entire plant receives the necessary light exposure, which is directly linked to the abundance of flowers produced in the spring. Proper separation is also a preventative measure against poor air circulation, which can otherwise create conditions favorable for the development of fungal diseases. For smaller, compact varieties, spacing should be set at their full mature spread, typically 4 to 6 feet apart.
Spacing Requirements for Dense Hedges
Creating a dense, unbroken visual screen or hedge requires intentionally crowding the forsythia plants to encourage their canopies to intermingle. For a quick, full, and informal hedge using standard, large varieties, plants should be spaced significantly closer, typically between 3 and 5 feet apart. This closer spacing forces the individual shrubs to grow together, creating a thick, uniform wall of foliage and flowers.
For a formal, dense, and rapidly established barrier, some horticulturists recommend spacing plants as close as 1.5 to 2 feet apart, especially for smaller or bare-root stock. This proximity ensures the stems knit together quickly to form an opaque screen. While this method increases density, it necessitates a more aggressive annual pruning regimen immediately after blooming to maintain the hedge’s shape and encourage healthy, vigorous new growth.
Preparing the Site for Planting
Once the correct spacing has been determined, proper site preparation is required to ensure the plant establishes a strong root system. The planting hole should be dug at least twice as wide as the nursery container or root ball, but it should be no deeper than the root ball itself. This wide, shallow hole provides loose, uncompacted soil, making it easier for the roots to spread laterally into the surrounding ground.
Incorporating organic matter, such as compost, into the soil removed from the hole improves both the fertility and the drainage of the planting medium. The shrub must be placed so that the top of the root crown is level with or slightly above the surrounding grade. This prevents the trunk from sitting in water and reduces the risk of root rot. After backfilling the hole, the soil should be lightly tamped to eliminate air pockets and then thoroughly watered to settle the soil around the roots.