The Skyrocket Juniper (Juniperus scopulorum ‘Skyrocket’) is a distinctive cultivar prized for its extremely narrow, upright growth habit. This columnar evergreen is a popular choice for both residential and commercial landscapes because it provides a strong vertical element. Its signature form makes it sought after where a tall, slender plant is desired without extensive lateral space. Understanding its ultimate size is helpful when planning placement.
Mature Height and Spread
The most distinguishing feature of the Skyrocket Juniper is its exceptionally narrow width at maturity. Under typical growing conditions, the plant will reach a height of between 15 and 20 feet, though some specimens in ideal environments may grow taller over many decades. The cultivar’s width is remarkably tight, generally spreading to only 2 to 4 feet across. This characteristic makes the plant resemble a slender spire. The plant naturally maintains this tight, columnar structure without the need for significant trimming or shaping.
Growth Rate and Environmental Influence
The process of reaching these final dimensions occurs at a medium speed, making it a manageable addition to most gardens. Under favorable conditions, the Skyrocket Juniper exhibits an average annual growth rate of approximately 12 to 18 inches per year. This steady pace allows the plant to achieve a substantial height relatively quickly compared to many other slow-growing conifers.
To reach its full potential height and maintain dense foliage, the juniper requires full sun exposure (at least six hours of direct sunlight daily). While it is adaptable to various soil types, the planting location must offer excellent drainage to prevent root issues. This cultivar is tolerant of drought once established, but consistent watering is necessary during its first few years to encourage a robust root system. Failure to provide adequate sunlight or well-drained soil can result in slower growth and a less dense, more open structure.
Pruning and Shape Management
The Skyrocket Juniper is valued for the self-maintaining nature of its narrow, upright shape, meaning structural pruning is rarely necessary. Intervention typically focuses on managing its width slightly or removing wood that is dead, diseased, or damaged. Pruning should always be performed with caution, as junipers do not produce new growth from old wood that lacks green foliage. Cutting back into this bare wood will result in a permanent, unsightly bare spot.
If a slight reduction in width is desired, a light annual shearing of the new growth tips can be performed in the early spring before new buds open. This technique helps to maintain the density of the foliage and prevents the structure from becoming too loose. Maintaining a tight habit is also a proactive measure against heavy snow or ice accumulation, which can weigh down branches and cause the narrow structure to split or splay open. For regions with prolonged heavy snow, securing the branches with twine or a similar binding material can offer protection.
Landscape Use and Spacing Requirements
The unique size and shape of the Skyrocket Juniper make it highly versatile for various landscape applications, particularly where space is limited. Its natural columnar form is well-suited for use as a vertical accent, drawing the eye upward and providing a striking contrast to lower, rounded shrubs. It is also frequently used to frame entryways or mark corners due to its formal appearance. The plant’s dense habit and tall stature make it an excellent choice for creating a privacy screen or windbreak in narrow yards.
When planting multiple junipers for a screen or hedge, proper spacing is important to ensure their health and long-term appearance. To create a solid, continuous screen, plants should be spaced approximately 3 to 4 feet apart, measuring from the center of one plant to the center of the next. This distance allows the foliage of neighboring plants to intermingle slightly, creating a dense barrier while still permitting enough air circulation to prevent disease. Planting too closely can lead to crowding and the loss of lower branches due to shading.