Junipers are some of the most popular privacy trees. This is especially true of mountain junipers, namely Blue Arrow Juniper and Skyrocket Juniper.
The main difference between Blue Arrow Juniper and Skyrocket Juniper is the color and size of the needles. The Blue Arrow Juniper has bluer needles, while the Skyrocket Juniper’s needles are more silvery green. Blue Arrow Juniper is also slightly narrower than Skyrocket Juniper.
The first (Blue Arrow) was selected from many seedlings in a nursery in Pennsylvania in the late 1940s. It has several advantages and is therefore considered an improved version of the competitor. This juniper has another famous name, Blue Arrow Eastern Red Cedar.
Skyrocket, in turn, was found in the Indiana wilderness as a natural mutation. The narrow and slender form attracted breeders’ attention, and the juniper was distributed very widely around the world. Another name is Rocky Mountain Juniper Skyrocket.
| 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 |
Blue Arrow Juniper and Skyrocket Juniper
Skyrocket has a broader growth habit
Both of these junipers are about the same height. After ten years of growth, they will reach 13-15 feet but will end up about 20 feet tall.
What sets them apart is their width. In the first few years, Skyrocket is narrow and columnar. It will start to expand and become 3-4 and even 5 feet wide, closer to ten years old.
At the same time, the Blue Arrow will have a slender shape throughout its life. It rarely exceeds two feet in width.
It follows that the Skyrocket will have a pyramidal shape, and to keep it columnar, you will have to cut it regularly. If you aim to make it into a hedge, you will not achieve a beautiful result despite the amount of work you will have to do.
The Blue Arrow, on the other hand, requires almost no annual pruning. Once you plant it, you will, after a while, get an excellent column that sometimes needs to be trimmed so that the plants grow to the same height.
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Blue Arrow has a slower growth rate
Skyrocket is growing faster than the competitor. Annual growth is 16-18 inches. Because of the rapid growth rate, it begins to grow more in width after a while.
Blue Arrow, on the other hand, rarely grows more than 10 inches annually. Over time, these junipers will have the same height, but Skyrocket will get to the maximum mark faster.
Skyrocket’s fast growth rate takes a toll on the strength of the annual branches. They do not have time to mature and thicken properly and, as a consequence, remain flexible for the winter. In heavy snowfall, a lot of snow is accumulated on the juniper, and the branches bend. In the worst case, they can even get damaged.
With Blue Arrow, there is no such problem. Its branches are harder and shorter, less snow accumulates on them, and can withstand more load. Of course, if there is a lot of snow, this variety can also get damaged (like any other plant). But it is still stronger than its competitor.
There were cases when the branches of Skyrocket sagged even from the wind and rain. Nothing like that happens to Blue Arrow.
The color isn’t the same
The color of the needles is the next small difference between Skyrocket and Blue Arrow.
Skyrocket has a grayish-green shade of needles. Sometimes it can even be a little silvery. This juniper looks especially beautiful when the sun is shining very bright.
Blue Arrow does not have a silver glow of needles, but it has a richer blue hue. Sometimes it can be bluish-green, and sometimes the blue is very pronounced.
The reason why these junipers have this unusual color is the wax coating on the needles. It protects the needles from intense sunlight, and the less sunlight there is, the greener the Skyrocket and Blue Arrow will be.
To get the exciting colors, you need to provide these plants with enough sun. For 4-6 USDA hardiness zones, they should get at least 10-12 hours of direct sunlight. If you live in the south (7-9 zones), give them 6-8 hours of sun.
Otherwise, both of today’s competitors will be green and may even have a loose structure as there won’t be enough sunshine to grow branches to form a dense plant.
In general, Blue Arrow has a more exciting foliage color than Skyrocket.
Similarities
In addition to their differences, Skyrocket and Blue Arrow have many similarities.
These junipers belong to the species Juniperus Scopulorum, which means that they grow mostly in rocky terrain where the soil is well-drained. So it would be best if you reproduced the same conditions. To improve your soil, you need to add 15-20% good quality compost to the planting hole.
Junipers are mostly drought-tolerant, but you need to water them if you want quick results (such as a hedge). This is especially important during periods of drought when the plant is not yet established. If it hasn’t rained in 7-10 days, water your juniper with 1-2 gallons of water, or more if it’s large.
Over time, when the juniper is established and reaches 3 to 4 feet in height, you don’t need to water at all.
One of the most important things for the survival of the juniper is to plant it properly. Gardeners plant junipers often, but after a short time, the plants die, and the gardeners do not know why, although it seems that everything was done correctly.
When planting juniper, it is crucial not to deepen the trunk base (the place where the trunk and roots connect) into the ground. Junipers are susceptible to moisture, and if the base of the trunk is buried, it will die. It follows that you should plant junipers just above 0.5-1 inch of garden surface.
Also, if you decide to mulch your plants, do not put mulch on the trunk. There should be a 1-inch gap.
Both of these junipers grow well in poor and sandy soil. But if you want beautiful plants, you should feed them once a year. It is ideal if you use a slow-release fertilizer. Apply it in early spring, and you don’t need to do anything else.
Don’t forget to protect Skyrocket and Blue Arrow from diseases and pests. Neem oil does a good job; one or two treatments a year is enough. If the infestation is severe, you should use a stronger treatment.