How to Plant, Grow, and Care for ‘Skyrocket’ Juniper

Columnar trees are indispensable in the yard! They’re ideal in a wide range of locations. Use them to mark the entrance to a walkway, arrange them in a row to create a living hedge, or use a single specimen as a focal point.

‘Skyrocket’ juniper is among the narrowest, most columnar trees available. These junipers have upright branches that grow close to the central trunk, creating structures similar to Italian cypresses. If Italian cypresses struggle in your garden, consider ‘Skyrocket’ junipers instead.

Cold-hardy, drought-tolerant, and relatively pest-free, this juniper variety is exceptional in the home garden. Find potted plants at your local nursery, search online for healthy specimens, or ask your neighbors for cuttings.

What Is It?

‘Skyrocket’ juniper performs best in temperate climates in USDA hardiness zones 4 through 9. This woody specimen will last many years in your garden, adding structure and ornamental beauty wherever it grows.

Native Area

There is some confusion about this tree’s origin. Most horticulturalists believe it to be a variety of the western juniper, though some consider it a cultivar of the eastern red cedar, Juniperus virginiana. Maybe someday, botanists can test the tree for its true genetics!  

Most horticulturalists agree this tree is a variety of the native Rocky Mountain juniper, Juniperus scopulorum. It’s an ornamental evergreen that grows well outside the native species’ original habitat, making it perfect for gardens throughout the United States. 

Juniperus scopulorum has a native range throughout the West, from Canada south through the Rocky Mountains. You’ll see ‘Skyrocket’ commonly available in shrub and tree nurseries in the western U.S. They’re also available online and from specialty conifer growers in eastern states. 

‘Skyrocket’ juniper dislikes high humidity during summer and wet soils. It’s not a good choice for southern gardens with muggy conditions during the growing season. Consider other columnar trees that grow well in the region. Narrow varieties of the eastern red cedar, like ‘Taylor,’ will do well. 

Characteristics

This columnar cultivar grows lush, evergreen foliage with blue-gray hues. It stands out in the landscape, as it’s much bluer than other coniferous species. The color is similar to that of the Colorado blue spruce. Rich, vibrant, and alluring, the foliage sprays are attractive in formal, informal, and cottage-style gardens.

The scaly foliage sprouts from woody limbs that grow upright. They rarely spread out, save for when ice or snow weighs on them and pulls them down. Male cones sprout in spring and release pollen onto nearby female junipers to fertilize their cones. 

Narrow and slow-growing, this tree is ideal for small spaces. It has a mature height of up to 30 feet in optimal conditions and a narrow width of two to three feet after many decades of growth. They’re pencil-thin compared to many other columnar species. 

Planting

Because ‘Skyrocket’ is a juniper cultivar, you can’t grow it from seeds. Seedlings may grow differently from their parents. Propagate it from cuttings or find potted plants at a local nursery instead of using seeds. If you can’t locate this variety, consider a similar columnar juniper like ‘Blue Arrow’ or ‘Gray Gleam.’

Preparing the Site

Before transplanting, some site preparation will set your plants up for success. The best growing area will have well-draining soil without standing water. In poor soils, consider amending the surface with thick layers of mulch a few weeks or months before planting. The mulch will decay over time, creating loose, porous dirt that drains well. 

If the area is particularly soggy, consider an alternative spot with well-drained soil for these junipers. They tolerate many different soil conditions, so long as the area stays relatively dry without standing water. Clay, silt, and loam are okay, though root rot is more common in clay-heavy locations. 

Transplanting

Once the site is ready, begin the transplanting process by digging a hole. You want a hole as deep and twice as wide as your plant’s rootball. Avoid amending the planting hole with mulch or amendments, as they can constrict the roots underground. Use your garden’s native soil, and amend the site after planting. 

Place the rootball in the hole, backfill the edges with soil, then water your tree well. Some specimens may require staking to stay upright while they adapt to the new location. They’ll typically stand upright after a few weeks when their roots sprout new fragments underground to anchor them in place. 

After transplanting, add a protective organic mulch on top of the soil. Compost, leaf mold, or wood chips work well. Leave space around the tree’s crown, and keep the layer between two and three inches thick. 

How to Grow

This woody specimen thrives with little pampering. Set it up for success from the start, and it’ll require few resources during its lifetime. It may not need additional irrigation in some gardens, it rarely needs pruning, and it thrives under constant direct sunlight! 

Light

The columnar ‘Skyrocket’ juniper prefers full sun to grow its best. Ensure each of your trees has six to eight hours of daily direct sunlight. The specimens may grow weak and leggy in partial shade, and unhealthy specimens will attract pests. 

This tree may require shade on hot afternoons during its first summer. The harsh afternoon sun can burn the foliage and shock the new tree, causing poor growth or premature death. Umbrellas easily provide shade, though shade cloths or canopies work well too. The tree will tolerate the afternoon sun after it establishes itself. 

Water

Excess moisture can cause root rot in junipers. They prefer free-draining soil without standing water. ‘Skyrocket’ specimens may need irrigation in their first year, though they’re incredibly drought-tolerant after establishing themselves. 

If the soil surface is moist, it’s best not to water. Wait until the ground dries a few inches down before irrigating the site. Avoid excess watering in winter, as wet soil with low temperatures can kill the thriving trees. 

Soil

These woody trees grow in a wide range of soil conditions. The most important factor is the average moisture content. Average or dry soils are best, as they match the species’ native range in the Rocky Mountains. Soils on mountainsides are gritty, rocky, and free-draining. 

Garden specimens tolerate clay, sand, or silt-heavy locations. So long as the area remains relatively dry throughout the year, your trees will perform well for many more seasons. They’ll need little water in clay soils, average amounts in loam, and extra water in sandy sites.  

Fertilizing

Fertilizer isn’t necessary, though it helps the specimens remain vigorous throughout the year. Apply a low dose of tree or shrub fertilizer in early spring before new growth emerges. An organic fertilizer with mycorrhizae is best for helping the tree remain healthy. 

You don’t need to fertilize if you add compost once a year. The compost provides nutrients while boosting the soil’s structure and drainage capabilities. It’s the perfect amendment for home gardens, and it’s incredibly easy to make! 

Maintenance

Outside of watering and fertilizing, there’s little else you’ll need to do to take care of your woody specimens. Their thin, narrow shape requires little pruning. Occasionally, a branch may fall before growing upright again. Simply prune it off to maintain the original shape.

Propagation

As we mentioned above, it’s impossible to grow ‘Skyrocket’ from seeds. You may use two propagation methods, taking cuttings and air layering, to make new plants from your existing ones. 

Cuttings

Cuttings are relatively easy to propagate, though they require time and patience to root. Start by sourcing stems anywhere from two inches to five feet long, and strip them of old growth. You may take cuttings any time of the year, though they’re most successful at rooting in the fall or winter. 

Place the cut stems in pots with coarse sand and keep them moist, but not soggy. Ensure the sand stays between 60-65°F (16-18°C) to ensure the cut stems heal and form roots without rotting. 

This is the only time high humidity is ideal for ‘Skyrocket’ junipers, as it helps them stay turgid despite their lack of roots. Place them in a cold frame or greenhouse, or cover them with plastic domes or pots to trap the humidity. 

Roots should form after a few weeks, after which new growth will emerge! Transplant the cuttings after they’re well rooted, anywhere from a few months to a year after starting them. 

Air Layering

Air layering involves letting the tree do the work of forming roots, so you don’t have to baby cuttings! Instead of removing stems from the plant, you’ll strip them of bark and cover them so they form roots while still growing on the original tree. 

Start by locating parts of the tree with healthy, vibrant foliage. Choose an offshoot rather than the main trunk, as you’ll have to prune the branch after roots form. Strip the bark in a small circle around the branch, ensuring the strip goes all the way around it. 

Cover the stripped portion with moss, potting soil, or a similar medium, and moisten it like a wrung-out sponge. Cover the medium with plastic wrap, and duct tape the wrap in place. Roots should form after a month or more, after which you can prune the rooted branch off the main plant and transplant it into your garden. 

Common Problems

Not many pests or diseases target these trees, though they may affect unhealthy specimens. Rotting, dying, or establishing plants are especially weak, making them easy targets. Protect your junipers by keeping them happy, healthy, and disease-free.

Pests

Aphids aren’t particularly troublesome, as cold temperatures kill them in the fall and winter. Others are particularly troublesome, like spider mites, scale, bagworms, webworms, and twig borers. Horticultural oils like neem work well in killing and preventing pests. Follow the product’s instructions for proper dosage and application rates.

Extreme infestations call for the removal of the afflicted tree. Scales and spider mites are difficult to remove because they’re small and mighty; they resist most treatments and reinfest the site. Remove the afflicted specimens and inspect your yard. Consider fixing the underlying issues leading to weak juniper growth before planting new trees. 

Diseases

Blight and rust are two common afflictions of ‘Skyrocket’ junipers in poor growing conditions where the diseases are present. Rust causes galls to form on infected branches. They ooze orange, webbed secretions in spring that release spores throughout your yard. Remove the galls to prevent future infections.

Blights are caused by fungi, too. Symptoms include browning tips, cankers, and a lack of new growth. Blights are common in wet, humid gardens where water droplets remain on the foliage. Avoid using overhead sprinklers, and space the trees properly to prevent infections. If blight occurs in wet springs or autumns, organic anti-fungal sprays help mitigate the issue. 

Cultural Issues

Root rot is the most common problem for ‘Skyrocket.’ It occurs when roots sit in stagnant water; unable to breathe, they die out belowground. By the time you notice the tree performing poorly, it’s likely its roots are already rotting.

Root rot is easily preventable with the right soil. Plant your tree in well-draining or dry sites, as it performs best with little moisture throughout the year.

Frequently Asked Questions