The evergreen shrub that is the Juniperus horizontalis ‘Wiltonii’ is widely popular. This is due to its hardiness and versatility. Other ground covering plants will find it hard to compete.
More commonly known as the Blue Rug Juniper or the Creeping or Carpet Juniper, this shrub is as its name describes.
The Juniperus horizontalis ‘Wiltonii’ features striking silvery-blue foliage. This color, however, is known to darken to a more purple shade in the colder seasons.
The Blue Rug Juniper can be found natively growing anywhere from Canada, Alaska, and the northern parts of the United States.
These northern parts include New York, New England, and even the Great Lakes. Being native to such a vast space is likely why this shrub is so versatile.
Founded by Jacob van Heiningen in 1914, the Juniperus horizontalis ‘Wiltonii’ was named with a sense of humor. Jacob called the shrub ‘Wiltonii’ after his town of Wilton as well as the famous store Wilton Carpets. He referenced the latter due to the appearance of the plant.
When growing as a groundcover, the Juniperus horizontalis ‘Wiltonii’ tends to look like a carpet. The joke has been kept alive through the years with its common name, Blue Rug Juniper.
Hailed as a popular groundcover, this shrub has a growth habit and sizing to back this up.
Being a shrub, you may find it strange to want to use the Blue Rug Juniper as a groundcover. However, this is due to its low growing height.
Where this shrub lacks in height, it makes up for in length or spread. Juniperus horizontalis ‘Wiltonii’ only reaches heights between 7.5cm and 15cm (3in and 6in). But, it has a spreading distance of anywhere between 1.5m and 3m (5ft and 10ft).
The Blue Rug Juniper’s growth size tells a lot about its growing habit. Unlike your everyday shrub, the Juniperus horizontalis ‘Wiltonii’ grows, well, horizontally.
It has a trailing or creeping growth habit. This growing habit makes the Blue Rug Juniper the ideal plant for otherwise obscene locations.
These locations include retaining walls, rocky areas, hills or slopes, and more. The Juniperus horizontalis ‘Wiltonii’ is a super solution for areas where it is hard to grow anything else.
What makes them the best choice is that they are hardy and low maintenance.
- 1 Juniperus horizontalis ‘Wiltonii’ Care
- 2 Frequently asked questions about the Blue Rug Juniper
- 3 Conclusion
Juniperus horizontalis ‘Wiltonii’ Care
To keep the Blue Rug Juniper looking great is fairly easy, as these shrubs are super low maintenance. You could pretty much plant this shrub anywhere and it will thrive. All it asks for is well-draining soil, it will not tolerate wet or soggy roots. And access to a sizable amount of time in full sun. A shaded area is not the way to go for this plant.
The Juniperus horizotalis ‘Wiltonii’ is almost like a miracle plant. As long as the soil your Blue Rug Juniper is in is well-draining, you will find the shrub is otherwise not fussy. From rocky or gravelly type soils to sandy or poor soils, the Blue Rug Juniper will grow without much care.
They are widely adaptable but are not at all tolerant of having their roots constantly wet. Standing in water must be avoided. Other than this, there are no other serious key things to note.
But, as with all plants, the Juniperus horizontalis ‘Wiltonii’ does have its ideal conditions. Meeting this shrub’s ideals would result in an exquisitely thriving plant, but it is not absolutely necessary.
This adds to what makes the Blue Rug Juniper so great.
These shrubs are salt-tolerant and grow best if planted near areas that are salted.
The Blue Rug Juniper also prefers a soil with a slightly acidic pH level. You can not go wrong with soil that is rocky, sandy, and dry, they love it.
Aside from the Juniperus horizontalis ‘Wiltonii’s’ adaptability to a variety of different soils, they are also known to prevent soil erosion.
For best results, you should only water the Blue Rug Juniper if it has not rained recently and if you have checked its soil. This shrub does not do well in constantly moist soil conditions. So, before you think of watering it, check the soil.
If the soil around your Juniperus horizontalis ‘Wiltonii’ still feels slightly moist, leave it be. It is a drought-tolerant plant. It would rather go without water for another day or two than be overwatered.
Typically you will not need to water the Blue Rug Juniper more than once a week. This includes a natural watering from Mother Nature. If the soil is of heavier consistency, watering may only be necessary once a month.
In extreme heat, however, your Blue Rug Juniper may require a bit more water. The best way to water this shrub is to give it a deep watering.
Shrubs that are not yet established, will require more frequent watering. Watering these newer plants once every two to four days will aid in growing a deep and extensive root system.
The Blue Rug Juniper, again, is not too phased about particulars. They are hardy in conditions from subtropical temperatures to the polar opposite, extreme cold.
These shrubs can withstand frost and snow too and are hardy to temperatures as low as -40°C (-40°F).
It really does not matter where you are, this plant will adapt and grow without problems. Juniperus horizontalis ‘Wiltonii’ will even endure fluctuating temperatures.
To name a few other things this plant will endure are strong sunlight with arid conditions and high altitudes.
Exposure to full sun is preferred. The Blue Rug Juniper will not fair well in shade. Any other spot will do except a shaded one. From dry to moist conditions, salt-air environments, and urban pollution, this shrub will tolerate it.
For a hillside or slope that proves difficult for plants to grow, the Juniperus horizontalis ‘Wiltonii’ is recommended.
It grows in a manner that is cascading and downhill. The shrub conforms to the shape of the ground it is planted on.
Blue Rug Juniper does well in a variety of landscaping applications. Including, but not limited to, mass planting, rock gardens, border edging, ground cover, and general garden use. If planted in an appropriate place, this shrub will be a flowing, evergreen, and expansive carpet.
Although used as a ground-covering plant, the Juniperus horizontalis ‘Wiltonii’ does not cope well where footfall is high. Other than that, the Blue Rug Juniper will thrive in many areas and conditions. Provided it receives its preferred full and direct sunlight.
Juniperus horizontalis ‘Wiltonii’ shrubs are low maintenance. Depending on your preference, you can either prune it or not. To keep it looking tidy, good housekeeping practices should be maintained.
Remove leaves, weeds, and grass as you spot them and trim the branchlets as need be.
If you are going for a more natural look, allowing the Blue Rug Juniper to grow and develop on its own is the key.
Although, it is always a good idea to keep a watch and trim any branchlets that are spreading where they should not be. This is especially necessary if the shrub is grown edging a path or roadway.
Used as a ground cover, the Juniperus horizontalis ‘Wiltonii’ is unlike others. It does not require mowing. Pruning may also be necessary in the event your shrub is suffering from a disease.
Juniperus horizontalis ‘Wiltonii’ rarely require fertilizing. It is another case of if you do, you do and if you do not it does not make much difference. If you do not fertilize your Blue Rug Juniper, it is not going to hold it against you. It will continue to grow at a steady pace.
If you do wish to feed your Juniperus horizontalis ‘Wiltonii’, however, they are only able to use a small amount at a time. This is due to their evergreen nature.
In the case of young Blue Rug Junipers, it is recommended that you use mulch. The mulch should be spread between each young plant while avoiding the covering of any branches. The benefit of the mulch is that not only does it reduce the growth of weeds, but it also conserves the moisture in the soil.
When deciding on which fertilizer to use, you should always opt for one that is organic. At most you should feed your Juniperus horizontalis ‘Wiltonii’ twice a year. Once in the early spring and again during autumn will be ample.
The only reason you would have to fertilize the Blue Rug Juniper is if you thought its foliage could do with a bit of a boost. Otherwise, this shrub grows well without the aid of fertilizer.
Planting the Juniperus horizontalis ‘Wiltonii’
When it comes to planting the Juniperus horizontalis ‘Wiltonii’, there are a few things to take into consideration. Aside from providing it with its ideal living conditions of soil, water, and so on. The time of year at which you plant the Blue Rug Juniper, for instance, should be taken into account.
The planting time will depend on the condition of the Juniperus horizontalis ‘Wiltonii’. In the case of a bare root Blue Rug Juniper, it is best planted during the winter months. This is the plant’s dormant period.
However, this is not the case for all forms. Some would do better if planted during autumn towards the early springtime.
Another factor that requires consideration is the depth of planting. The Blue Rug Juniper does not need to be planted very deep. The hole in which you plant your shrub should be about 5cm (2in) wide, but shallower than what the root is.
When planting multiple Blue Rug Junipers in an area, you need to allow a spacing of 1.5m to 2m (5ft to 7ft) between them. This is to accommodate the shrub’s spreading habit of growth and their overall spread at maturity.
It is possible to plant the Blue Rug Juniper closer together though. Doing so will decrease the time which it would normally take to cover an area. It may also aid in the appearance of the plant to be bushier and more full looking.
Depending on the space left between each of the plants, it may take a few years for the Juniperus horizontalis ‘Wiltonii’ to fill in the desired area. But, once established, they are perfect for keeping your plant bed weed-free.
Planting the Blue Rug Juniper on a slope or hill may result in some of them sticking sideways out of the ground. But, do not worry, they will be perfectly fine. The shrub will grow downwards and connect with one another.
To propagate the Juniperus horizontalis ‘Wiltonii’ requires patience. These shrubs can be propagated through cuttings but you should be prepared for a lengthy wait. The reason this process takes a while is that the Blue Rug Juniper is known to be particularly slow to root.
Although cuttings can be taken at any time of year, if you are wanting to transplant the shrub you should hurry up and wait. Transplanting the Juniperus horizontalis ‘Wiltonii’ cutting to its permanent position will only be possible after at least a year, possibly even two.
Pests and diseases
Blue Rug Junipers are not seriously affected by many pests or diseases. Although there are a few you should keep an eye out for.
Pests that may occasionally bother your Juniperus horizontalis ‘Wiltonii’ may include spider mites, webworms, bagworms, and aphids.
With regards to problematic diseases, these shrubs can be susceptible to root rot and blights. The term blights refer to the dieback of the shrub’s stem tips. These issues tend to occur either when the plant is overwatered or during an unusually wet or rainy period.
Frequently asked questions about the Blue Rug Juniper
How do you treat Juniper blight?
The way to go about treating your Blue Rug Juniper that is suffering from blight is to prune away the affected areas. Be sure not to allow the affected branches to come into contact with the rest of the healthy shrub. You will need to sterilize your pruning shears before using them again.
Is it necessary to wear gloves when handling the Juniperus horizontalis ‘Wiltonii’?
Although it is not a necessity, it is recommended to wear gloves while working with the Blue Rug Juniper. This variety of Juniper is softer but it may still be cause for irritation. It is more so important if you have sensitive skin.
The Juniperus horizontalis ‘Wiltonii’ is likely to grow where no other plant wants to. It is extremely versatile. This not only refers to its ability to adapt to environmental conditions. The Blue Rug Juniper is also versatile in landscaping locations.
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.