Junipers are highly favored as privacy trees, particularly the mountain varieties such as Blue Arrow Juniper and Skyrocket Juniper.
The main difference between Blue Arrow Juniper and Skyrocket Juniper lies in their growth habits and appearance. Blue Arrow Juniper, known for its striking blue-green foliage, has a very narrow, columnar form, growing up to 12-15 feet tall but only 2-3 feet wide. This makes it ideal for creating vertical accents in landscapes.
Skyrocket Juniper, on the other hand, is slightly less narrow, with a height of up to 20 feet and a width of about 4 feet. Its foliage is also a blue-green color but tends to be a bit more silvery than Blue Arrow.
| Blue Arrow Juniper | Skyrocket Juniper | |
| USDA Hardiness zone | 4-9 | 4-9 |
| Mature height | 15-20′ (4.5-6 m) | 15-20′ (4.5-6 m) |
| Mature width | 2-3′ (0.6-0.9 m) | 3-5′ (0.9-1.5 m) |
| Growth rate | medium | fast |
| Color | blue-green | silver-green |
| Light exposure | full sun, partial shade | full sun, partial shade |
| Soil | well-drained | well-drained |
| Soil pH | 6.0-7.0 | 6.0-7.0 |
| Watering | One time per week in a drought | One time per week in a drought |
| Diseases | fungus | fungus |
| Pests | insects, mites | insects, mites |
Growth Habit
Both the Blue Arrow and Skyrocket Junipers reach similar heights, growing to 13-15 feet in the first decade and eventually maturing to around 20 feet. Their width, however, distinguishes them significantly. Initially, the Skyrocket is narrow, but as it nears the ten-year mark, it broadens to 3-4 feet, sometimes even 5 feet. In contrast, the Blue Arrow maintains a consistently slender profile, seldom exceeding two feet in width.
This difference in width means the Skyrocket develops a pyramidal shape over time, requiring regular trimming to maintain a columnar form. Attempting to shape it into a hedge may not yield aesthetically pleasing results, despite considerable effort. The Blue Arrow, conversely, needs little to no annual pruning. Once planted, it naturally forms a striking, upright column with minimal upkeep.
Growth Rate
The Skyrocket outpaces its counterpart with an annual growth rate of 16-18 inches, leading it to reach its maximum height more swiftly. As it grows quickly, it also begins to widen over time. In contrast, the Blue Arrow typically sees a slower growth of no more than 10 inches per year, leading both varieties to eventually reach similar heights, albeit at different rates.
The rapid growth of the Skyrocket, however, affects the robustness of its yearly branches, which don’t have sufficient time to thicken and mature. This results in branches that remain flexible during winter. In heavy snow, these branches can bend or even break under the weight, as they accumulate more snow.
On the other hand, the Blue Arrow’s branches are tougher and shorter, bearing less snow and more weight, thus offering greater resistance. While heavy snowfall can still pose a risk to any plant, the Blue Arrow is generally more resilient than the Skyrocket.
Color
The Skyrocket Juniper features needles with a grayish-green hue, often with a hint of silver, which looks particularly stunning in bright sunlight. The Blue Arrow, while lacking the silvery sheen, boasts a more vivid blue color. Its needles range from bluish-green to a deep, pronounced blue.
This unique coloring in both junipers is due to a wax coating on the needles, serving as a shield against intense sunlight. Consequently, the less sunlight they receive, the greener the needles of both Skyrocket and Blue Arrow appear. To truly bring out their distinctive colors, these plants need ample sunlight, ideally at least 8 hours of direct exposure daily.
Overall, the Blue Arrow tends to have a more striking foliage color compared to the Skyrocket, making it a standout choice for adding vibrant hues to your garden.
Origin
The Blue Arrow Juniper emerged as a standout among many seedlings at a nursery in Pennsylvania during the late 1940s. Boasting several benefits, it is often regarded as an enhanced version of its counterparts. This variety is also widely known as the Blue Arrow Eastern Red Cedar.
Conversely, the Skyrocket was discovered as a natural mutation in the wilds of Indiana. Its slender and narrow form caught the attention of breeders, leading to its widespread distribution globally. It is also referred to as the Rocky Mountain Juniper Skyrocket.
Similarities
Skyrocket and Blue Arrow Junipers, despite their differences, share many similarities. Both belong to the Juniperus Scopulorum species, typically found in rocky areas with well-drained soil. Replicating these conditions is beneficial for their growth.
These junipers are generally drought-tolerant, but for quicker growth, such as forming a hedge, regular watering is essential. This is especially crucial during drought periods or before the plant is fully established. If there’s no rain for 7-10 days, water your juniper with 1-2 gallons, or more for larger plants.
When mulching around these junipers, ensure there’s a 1-inch gap between the mulch and the trunk to prevent moisture buildup.
Both Skyrocket and Blue Arrow thrive in poor and sandy soils, but for optimal health and appearance, annual feeding is recommended. Using a slow-release fertilizer in early spring is ideal for nourishing these plants without the need for additional care throughout the year.
