Read the commented creeping juniper profile here for useful information about growth, needles, flowers and fruits. You can find out how to properly plant, care for and cut Juniperus horizontalis here.
What is creeping juniper and how is it used?
Creeping juniper (Juniperus horizontalis) is an evergreen, easy-care conifer that can be used as a ground cover, bonsai or potted plant. It grows 20-50 cm high and 100-300 cm wide and prefers sunny to partially shaded locations with well-drained soil. The creeping juniper is hardy, tolerates cutting and is poisonous.
Profile
- Scientific name: Juniperus horizontalis
- Genus: Juniper (Juniperus)
- Family: Cypress family (Cupressaceae)
- Growth type: conifer, dwarf shrub
- Growth height: 20 cm to 50 cm
- Growth width: 100 cm to 300 cm
- Leaves: evergreen needles
- Flowers: dioecious, inconspicuous
- Fruits: cones
- Toxicity: poisonous
- Winter hardiness: hardy
- Use: ground cover, grave planting, pot
Growth
Creeping juniper comes from North America. There the conifer colonizes barren slopes, sand dunes and river banks throughout Canada, Alaska and Massachusetts. In this country, Juniperus horizontalis is one of the most popular conifers from the cypress family. Hobby gardeners value the dwarf shrub as a classic ground cover, useful problem solver and easy-care design element. The following overview summarizes all the important facts about growth:
- Growth type: evergreen, low shrub with creeping roots and densely branched branches that partially overlap one another.
- Growth height: 20 cm to 50 cm.
- Growth width: 100 cm to 300 cm.
- Growth speed: 5 cm to 15 cm.
- Root system: Deep-rooted plant with numerous runners.
- Bark: brown, smooth, later flaking.
- Gardenically interesting properties: hardy, undemanding, tolerates cutting, hard-wearing, heat-tolerant, resistant to urban climates, poisonous.
leaves
On its prostrate branches, creeping juniper produces two different types of leaves with these characteristics:
- Leaf shape A: pointed-needle-shaped, 4 mm to 8 mm long, close fitting to slightly protruding.
- Leaf shape B: blunt-rounded, 1.5 mm to 2 mm long, scale-like, overlapping.
- Leaf color: green to dark green, reddish-purple to bronze in winter.
Numerous varieties expand the color palette with decorative nuances from subtle bluish to intense yellow.
Flowers
Like all junipers, Juniperus horizontalis is a dioecious, segregated shrub. The conifer bears either male or female flowers with these characteristics:
- Male flowers: yellowish cones sitting on the short stem.
- Female flowers: yellowish-reddish cones made up of three cone scales, ovate to spherical.
- Flowering period: April to June.
Fruits
Fertilized flowers of a female creeping juniper transform into berry-shaped fruits with these attributes:
- Botanical status: Berry cones
- Fruit shape: stalked, spherical to ovoid, 5 mm to 7 mm in diameter.
- Fruit color: bluish to blue-black.
- Maturation period: 2 to 3 years.
- Special feature: poisonous
Each soft, resinous mini cone contains one to three seeds. The 4 mm to 5 mm small seeds contain the highest concentration of poison of all plant parts of a Juniperus horizontalis.
Usage
Its evergreen understatement makes creeping juniper a versatile design component in beds and on the balcony. Get inspired by these options of creative and practical uses:
| Garden | Idea | Balcony/Terrace | Idea |
|---|---|---|---|
| Rock Garden | Green boulders | Bucket | beautifully trained for bonsai |
| gravel bed | step-friendly path border | Flower box | evergreen hanging plant |
| Japanese Garden | evergreen ground cover | Wooden trough | Underplanting privacy plants |
| Natural Garden | Green drywall | Pot | Mini variety in a zinc pot as a table decoration |
| Modern Garden | stylish bonsai | ||
| Urban Garden | easy-care roof garden greenery | ||
| Grave planting | wide-covering all-season ground cover |
Every creeping juniper has the potential to become an artistic bonsai, as the following video shows:
Video: Bargain creeping juniper from the hardware store on the way to becoming a bonsai work of art
Planting creeping juniper
You can buy creeping juniper ready to plant at the nursery at any time of the year. Due to its creeping roots, the shrub is usually offered as a container plant. This has the advantage that with Juniperus horizontalis you are not tied to a fixed planting time. Where and how to plant creeping juniper correctly, read here:
Location and soil
These are the location preferences of creeping juniper:
- Sun to partial shade (the needles die in a shady location).
- Normal garden soil, fresh, moist, well-drained and not too heavy.
- Exclusion criterion: waterlogging
Planting in the bed
It's so easy to plant creeping juniper in the bed:
- Place the potted root ball in water until no more air bubbles appear.
- Dig a pit with twice the diameter of the pot ball.
- Unpot the bush and plant it at the same depth as in the container.
- Press the soil with both hands and water thoroughly.
In lean, nutrient-poor locations, please add a handful of compost soil or horn shavings to the planting hole as starter fertilizer. Loosen heavy clay soil with sand or lava granules so that the creeping roots can build up well in all directions.
Planting in pots
Commercial conifer soil without peat is suitable as a potting substrate. The focus of planting is to protect against harmful waterlogging. Cover the bottom of the pot with broken clay, expanded clay or grit so that excess rain and irrigation water drains away quickly.
Excursus
Creeping juniper is not a host for pear trellis
One of the many advantages of creeping juniper is that the conifer is not a host plant for pear rust (Gymnosporangium fuscum). Juniperus horizontalis is not affected by the host-changing pathogens of the dreaded fungal disease, so there is no risk of infection for pear trees in the garden. Other types of juniper, however, do not escape unscathed. The main hosts for the dangerous rust fungi are Chinese juniper (Juniperus chinensis) and poison juniper (Juniperus sabina). Creeping juniper (Juniperus procumbens), also known commercially as Japanese creeping juniper, is also suspected.
Care for creeping juniper
Creeping juniper is very easy to care for. You should be a little concerned with water supply, nutrient supply and pruning care in order to have a conifer in top shape. It's worth taking a look at these tips about care and propagation:
Pouring
Water a young bush thoroughly when it is dry. As a deep-rooted plant, a creeping juniper later supplies itself with water. When grown in pots, the conifer depends on regular watering. Although the prostrate needle branches shade the soil, the substrate dries out in a sunny location. Do not feel any moisture in the top one or two centimeters of the plant soil, let normal tap water run onto the root disk until the first drops run out at the bottom.
Fertilize
As a ground cover, creeping juniper is grateful for liquid fertilizer. Raking in compost can damage creeping roots and shoots. Add conifer fertilizer to the irrigation water every four weeks from March to August. At the beginning of September, stop supplying nutrients so that the evergreen shoots mature before winter.
Cutting
Creeping juniper is compatible with pruning if you pay attention to this property: Conifers do not put on sleeping eyes and no longer sprout from unneedled branches. How to cut Juniperus horizontalis correctly:
- Conifers cut every 2 to 3 years between February and August.
- Thin out dead branches.
- Cut back unfavorable shoots that protrude out of shape.
- Place the scissors in the green needled area.
Wintering
In its North American native regions, creeping juniper has learned to survive unscathed in bitter frost. Due to a winter hardiness of up to -35° Celsius, you can remove winter protection measures from the care program.
Propagation
Hobby gardeners favor vegetative propagation through cuttings because the decorative properties of the mother plant are retained. Cracked cuttings are used, which root better than classic top cuttings. The following short instructions explain the correct procedure:
- Best time is from July to September.
- Tear off a 15 cm long side branch from the older, vital branch.
- Cut off the bark tongue, cut back the shoot tip by a third.
- Fill the cultivation pot with a mix of coniferous soil (€10.00 on Amazon), coconut soil and sand in equal parts.
- Place the cutting 2/3 into the substrate and water.
Under a transparent hood, in a partially shaded location at an average of 16° Celsius, root formation begins within four to six weeks.
Popular varieties
These creeping juniper varieties beautify rock gardens, balconies and resting places with tasteful color:
- Glauca: Blue creeping juniper with silvery-blue needles in every season, growth height up to 30 cm, growth width up to 200 cm.
- Mother of Load: Rarity with creamy yellow needles, beautiful grave planting, delicate and compact, growth height up to 15 cm, growth width up to 65 cm
- Wiltonii: Blue carpet juniper, bluish needles, grey-blue cones, forms dense mats, 20-30 cm high, 150 cm to 300 cm wide.
- Hughes: evergreen dwarf shrub with gray-green needles on creeping shoots, growth height up to 50 cm, growth width up to 250 cm.
- Blue Acres: extremely wide creeping juniper with blue-gray, soft needles, up to 300 cm wide, growth height up to 30 cm.
- Prince of Wales: colorful variety, green-blue needles turn reddish in winter, growth height up to 30 cm, growth width up to 250 cm.
FAQ
We would like to plant creeping juniper under a pear tree. Are there any concerns about pear grate?
You can safely plant Juniperus horizontalis as a ground cover under a pear tree. Creeping juniper is not one of the host plants for the pathogens of pear rust. The main vectors of the fungal infection are Chinese juniper (Juniperus chinensis), poison juniper (Juniperus sabina) and probably creeping juniper or Japanese creeping juniper (Juniperus procumbens).
How many creeping junipers should be planted for rapid greening of areas?
As a rule, the nursery recommends a plant requirement of 2 to 3 bushes per square meter for creeping juniper as a ground cover. Given the very slow growth, it takes a few years until a complete green cover develops. In order to completely green a bed area in as short a time as possible, you should double the number to 4 to 6 creeping junipers per square meter.
Can you transplant a five-year-old creeping juniper? What should you pay attention to?
In the first five years of growth, creeping juniper can cope with a change of location. The stress factor is at its lowest level if you transplant the conifer in February or March as soon as the ground has thawed. Loosen the soil with a digging fork. Now lift the root ball with as many runners as possible out of the ground. Dig a spacious planting pit at the new location. While maintaining the previous planting depth, place the creeping juniper in the ground and water. To compensate for the lost root mass, cut back the shrub in the green area.
Is creeping juniper poisonous?
All juniper species are poisonous. This also applies to creeping juniper (Juniperus horizontalis). The focus is on the berry-shaped fruits, which can cause nausea, vomiting and stomach cramps when consumed. An overdose can lead to kidney damage. However, creeping junipers bloom and fruit extremely rarely. As dioecious, separate-sex conifers, the poisonous fruits only form when males and females are in close proximity.
