The Moonglow Juniper is also known as Rocky Mountain Juniper.
The second name for the Moonglow Juniper is Juniperus scopulorum ‘Moonglow’, which is its botanical name with the reference ‘Moonglow’.
Let’s have a look at how to care for a Moonglow Juniper.
Moonglow Juniper Care
To care for Moonglow Juniper provide well-draining soil as they do not enjoy having their roots drenched in water. Water manually until they have been established. Make sure it gets about six hours of direct sunlight daily and ensure the temperature stays above -34°C (-30°F). Fertilize in early spring using a slow-release fertilizer.
Moonglow Juniper Care
Table of Contents
How to Care for Moonglow Juniper
Soil
A Moonglow Juniper needs well-draining soil.
Moonglow Junipers are not very picky when it comes to the soil they are planted in.
Provided that the soil has features for fast drainage, the Juniperus scopulorum ‘Moonglow’ will be happy.
These shrubs tolerate poor soils and will even do well in soils that are clay-based, loamy, compacted, or alkaline.
The only soil type Moonglow Juniper trees will not tolerate are ones that are constantly wet or soggy.
They do not take well to having their roots consistently standing in water.
Other than that, these trees will adapt to just about anything. They are also not particular about the pH levels of the soil.
Watering
Moonglow Juniper is best watered naturally through rainfall and does not need additional watering.
Although these trees are very drought resistant, the Juniperus scopulorum ‘Moonglow’ does still appreciate the occasional watering.
Generally, the Moonglow Juniper doe not need more water than what is provided through a good rain shower.
This is enough water to keep your shrub hydrated and it is not necessary for you to water it.
However, if your Juniperus scopulorum ‘Moonglow’ has not yet been established, watering will be required.
Watering your young Moonglow Juniper about once a week will be ideal and encourage the growth of an extensive system of roots.
This is only necessary if your young tree has experienced a rain shower.
Watering your Moonglow Juniper that has not yet been established will need to be done for the first two years.
After these initial two years, your Juniperus scopulorum ‘Moonglow’ can then be considered an established tree.
This means you will no longer be required to provide it with weekly watering.
It will do just fine being watered by mother nature and her rain.
Temperature
The Moonglow Juniper is hardy down to -30°F (-34.4°C).
These are incredibly hardy and adaptable trees.
Thus, the Juniperus scopulorum ‘Moonglow’ does not necessarily have a preferred temperature range.
It is likely that the Moonglow Juniper will thrive regardless of the region it is in.
However, your Moonglow Juniper may need a little bit more attention.
This is only if the area in which you grow this tree is known to have a lot of rain and experience excessively cold temperatures.
This combination of water and very cold temperatures will result in the tree receiving an ice covering.
Juniperus scopulorum ‘Moonglow’ is not known to tolerate these conditions for more than two days and will need to be protected.
This can be done by simply covering your tree.
In otherwise dry conditions these trees are cold-hardy right down to temperatures of –30°F (-34.4°C).
Light
Grow Moonglow Juniper in full sun.
There are very few places that the Juniperus scopulorum ‘Moonglow’ will not grow happily in.
Ideally, these trees should be planted in full sun.
Moonglow Junipers are sun-loving plants and do well with access to as much sunlight as possible, for as long as possible.
Daily exposure of six hours to eight hours of direct sunlight would be preferential for these trees.
That being said, they will not kick up a fuss should they end up in an area that is partially shaded.
Too much shade, however, may end up being detrimental to the health of your Juniperus scopulorum ‘Moonglow’.
Taking this preference into consideration, there is nothing else that you need to do for this tree.
But, there are numerous things the Moonglow Juniper can do for you. It has a range of uses other than just being an aesthetic addition to any landscape.
Juniperus scopulorum ‘Moonglow’ trees can be used as noise buffers and are in fact quite popular for this.
They can also be used for large-scale screenings, like windbreakers and even for erosion control.
But, that is not all, Moonglow Junipers can also be used for topiary at an entrance.
Or, on a much smaller scale, these trees are popularly used for the art of bonsai.
These trees are also known to grow well in a grouping environment.
This is due to their non-aggressive root system.
Juniperus scopulorum ‘Moonglow’ trees even have somewhat of a tolerance to urban pollution.
Whatever landscaping dilemma you may find yourself in, or even with no dilemma at all, the Moonglow Juniper tree will be the answer.
You can even plant them under powerlines!
There really is nothing that this tree will not adapt to and handle as long as its basic needs are met.
Pruning
Prune a Moonglow Juniper in early spring.
Juniperus scopulorum ‘Moonglow’ trees are super low maintenance.
They are not likely to require pruning often at all.
Moonglow Junipers do not shed their needle-like foliage so they do not even produce any litter to be cleaned either.
Pruning of the Juniperus scopulorum ‘Moonglow’ should only be done early in the spring.
Doing so at this time of the season allows the tree’s new growth enough time to harden off. The hardening off needs to be done before the winter months set in.
There are only a few reasons you may want to or need to prune this tree. In the case of it being shaped, annual pruning would be necessary in order to maintain your Moonglow Juniper’s desired shape.
The other time pruning your tree will be necessary is if it has diseased or dead branches.
You should also watch out for caterpillars. Branches that have been affected by caterpillars should be removed.
Doing so will help to avoid any further infestation.
It is best to keep in mind that different objectives for your Moonglow Juniper will require different methods of pruning.
If your Juniperus scopulorum ‘Moonglow’ is being grown as a hedge, it will need to be pruned differently to a tree that is being grown purely as a specimen form.
Fertilizer
Moonglow Juniper trees should be fertilized in the early spring just before the new growth begins.
Fertilizing your Moonglow Juniper is important as it ensures your shrub has maximum hardiness and health.
Using standard chemical fertilizers when the hot summer months are amidst is not recommended.
You risk harming the roots of your Juniperus scopulorum ‘Moonglow’.
Ideal plant food to use for your tree is one that is well-balanced and has extended-release properties.
Moonglow Junipers crave acidity, so choosing a fertilizer that would give your tree a bit of extra acid is preferred.
Provided you do not use it during the summer when there is a risk of burning the tree’s roots, chemical fertilizers can be used.
The other option available to use is organic fertilizers.
Organic fertilizers, such as manure or compost, are great as they are not only beneficial to the Juniperus scopulorum ‘Moonglow’.
These fertilizers also have the benefit of improving the condition of the soil.
For chemical fertilizers, one that is slow-releasing is ideal. These should only be applied once per year.
Never fertilize your Moonglow Juniper in the autumn months.
Autumn time is when these trees begin preparing themselves for their period of dormancy.
If you fertilize your Juniperus scopulorum ‘Moonglow’ during this time, new growth may be simulated which will be too weak to survive the winter.
Moonglow Juniper
The Moonglow Juniper fashions needle-shaped foliage of deep blueish-green color with a magnificent silvery tinge.
This silvery tinge of the tree’s dense foliage reflects the glow of the moon creating an almost magical appearance.
This reflection of the moonlight is where the common name ‘Moonglow’ originated from.
Native to various regions of North America, the Juniperus scopulorum ‘Moonglow’ is extremely hardy and adaptable.
This shrub has a slender form but is pyramidal in shape and grows to moderates heights.
The Moonglow Juniper is a slow-growing tree and has an average growth of 0.3m (2ft) per year.
You can expect your Juniperus scopulorum ‘Moonglow’ to reach heights between 10ft to 20ft (3m to 6m).
When left to their own devices, however, these trees can mature to heights of 30ft to 40ft (9m to 12m).
Although tall, Moonglow Junipers keep to a narrow width between 3ft to 10ft (0.9m to no more than 3m).
Or if left to mature naturally, they may reach widths of up to 15ft (4.5m).
Planting the Moonglow Juniper
Moonglow Junipers are not difficult to transplant and establish.
There are a couple of things that should be taken into consideration.
Firstly, the most common reason for a Juniperus scopulorum ‘Moonglow’ to not survive being transplanted is due to it being planted too deep.
These trees should be placed in a hole that is twice the size of their root ball.
This sizing refers to both the width and the depth of the hole.
As a guide, you should not plant your Juniperus scopulorum ‘Moonglow’ deeper than the soil line from its current potting.
There is another tip to tell if you have planted your new tree in a sufficiently shallow hole.
After backfilling the hole, you should still be able to some of the tree’s original soil.
If the soil you are planting your new Moonglow Juniper in is of poor quality, it is recommended that you subsidize this with either compost or topsoil.
Either of these should be used to backfill the hole rather than using the soil you had dug out.
Once you have backfilled the hole, you will need to give your Juniperus scopulorum ‘Moonglow’ a decent watering. Watering your plant deeply is necessary to ensure the soil is moist down to the bottom of the hole.
You will need to check the moisture regularly and water it to maintain an adequate level of moisture.
After about two years, your Moonglow Juniper should have established a good root system.
This means you will no longer need to actively water your tree, but rather leave it to be done during rain showers.
Moonglow Juniper: Pests and Diseases
According to Washington State University, the Moonglow Juniper is relatively free of pests and diseases. However…
Two pests that are attracted to the Moonglow Juniper, it is the juniper webworms and bagworm caterpillars.
Deers are not an issue for the Juniperus scopulorum ‘Moonglow’ as they are not enticed by these trees.
These insects are known to damage the Moonglow Juniper’s branches as well as their foliage.
Checking your tree periodically and removing branches that have been affected will prevent further and more severe infestation.
Moonglow Junipers are also susceptible to the disease twig blight as well as to some forms of tree rust.
Most commonly, Juniperus scopulorum ‘Moonglow’ trees may be affected by three types of tree rust known as hawthorn, cedar-apple, and quince rust.
Other diseases to watch out for are Phomopsis blight and canker.
Frequently Asked Questions About Moonglow Juniper
How do you propagate the Moonglow Juniper?
The Moonglow Juniper can be propagated through semi-hardwood cuttings. These cuttings will take about a year to develop roots. This process is a slow one and requires a lot of patience.
Conclusion About Moonglow Juniper
These silvery-blue trees that reflect the moon’s glow at night make for a magical addition to any garden.
Moonglow Junipers are hardy and unphased. They are likely to put up with just about anything.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.