Japanese Holly Ilex crenata Dark Green = 'Icoprins11' (PBR)
ABOUT
The plant known as Japanese holly 'Icoprins11' is recognized for its dense, compact, and rounded growth habit. The foliage consists of small, glossy leaves that are a rich, dark green color, contributing to its common name. These glossy leaves maintain their dark green hue throughout the year, offering a consistent and evergreen visual appeal. With a fine texture and a tight branching pattern, the plant creates a smooth, lush surface appearance. It is also worth noting that this variety is appreciated for its resistance to common diseases that affect other types in its family, making it a robust and attractive choice for a variety of landscaping designs. The overall appearance of Japanese holly 'Icoprins11' conveys a sense of elegance and resilience, which allows it to function beautifully as a low hedge or as an accent in garden compositions.
About this plant
NamesFamily
Aquifoliaceae
Synonyms
Japanese Holly, Box-leaved Holly, Dark Green Japanese Holly
Common names
Ilex crenata 'Dark Green', Ilex crenata 'Icoprins11'.
ToxicityTo humans
The common name for Ilex crenata 'Dark Green' (Icoprins11) is simply Japanese Holly. While the toxicity to humans specifically from this cultivar is not well-documented, hollies in general are considered to be mildly poisonous. The berries are the most toxic part, and if ingested, they can cause symptoms such as nausea, vomiting, diarrhea, and rarely, drowsiness. It’s important for individuals to avoid consuming any parts of the Japanese Holly plant. Due to its potential toxicity, keeping it out of reach of children who might be tempted to eat the attractive berries is advisable.
To pets
Japanese Holly, the common name for Ilex crenata 'Dark Green' (Icoprins11), is also toxic to pets including cats and dogs. Similar to its effects on humans, ingestion of any part of the plant, particularly the berries, can lead to gastrointestinal symptoms. These may include vomiting, diarrhea, and abdominal pain. If a pet consumes a large quantity of the berries or leaves, more serious symptoms could occur and veterinary attention should be sought. Owners should prevent pets from chewing on or eating any portion of the Japanese Holly to avoid these potential issues.
CharacteristicsLife cycle
Perennials
Foliage type
Evergreen
Color of leaves
Dark green
Flower color
White
Height
5 feet (1.52 meters)
Spread
4 feet (1.22 meters)
Plant type
Shrub
Hardiness zones
5
Native area
Asia
Benefits
General Benefits- Compact Growth Habit: Ilex crenata 'Dark Green'® grows in a dense, compact form, making it suitable for small gardens or limited spaces.
- Low Maintenance: The plant requires limited pruning and care once established, which is ideal for busy gardeners or those seeking low-effort landscaping.
- Evergreen Foliage: It retains its vibrant green leaves throughout the year, offering continual visual interest and a lush garden backdrop.
- Adaptability: This variety of holly is adaptable to a range of soil types, although it prefers well-drained conditions.
- Pest Resistance: Ilex crenata 'Dark Green'® is resistant to many common pests that affect other plants, reducing the need for chemical treatments.
- Versatility in Landscaping: Due to its shape and size, it can be used in various design elements, including hedges, topiaries, or as a stand-alone specimen.
- Cold Tolerance: It's tolerant of cold temperatures, making it suitable for a variety of climates and extending its potential range of use.
- Suitable for Containers: This holly can be grown in containers, where its size can be managed and it can provide structure to patios, balconies, or terraces.
- Excellent for Formal Gardens: It lends itself well to formal garden designs, especially for creating borders or geometric shapes.
- Dense Texture: The plant's dense leaf texture provides excellent coverage for ground and can help suppress weeds when used in mass plantings.
- Attracts Wildlife: While not its primary purpose, the plant can provide shelter for birds and other small wildlife within a garden setting.
- Good for Topiary: It is an excellent candidate for topiary projects due to its growth pattern and ability to tolerate shearing and shaping.
Medical PropertiesThis plant is not used for medical purposes.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Japanese holly can be used in bonsai cultivation due to its small leaves and ability to respond well to pruning and shaping.
- The dense foliage of Japanese holly makes it suitable for topiary designs in formal gardens.
- Its wood can be used in the creation of small carvings or inlaid decorative arts, taking advantage of its fine grain.
- Japanese holly is often used as a substitute for boxwood in parterres and knot gardens because of its similar appearance.
- The berries of the plant can be used in decorative crafts, but caution must be exercised as they are toxic if ingested.
- In landscape design, Japanese holly is used to create privacy screens or hedges.
- It can serve as a habitat and food source for birds, though the berries are not suited for human consumption.
- The plant can be used as ground cover in large garden spaces where low maintenance vegetation is desired.
- Japanese holly's evergreen nature makes it an ideal plant for winter gardens to provide year-round greenery.
- Because of its resistance to salt, Japanese holly is used in coastal areas for landscaping purposes.
Interesting Facts
Feng ShuiThe Japanese Holly is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Japanese Holly is not used in astrology practice.
Plant Symbolism- Protection: Ilex crenata, commonly known as Japanese Holly, is often considered a symbol of protection due to its spiky leaves, which are thought to ward off negative energy and evil spirits.
- Good Fortune: In certain cultures, hollies like the Japanese Holly are associated with good luck and are often planted near homes to bring prosperity to the residents.
- Endurance: The Japanese Holly represents endurance and the ability to adapt to challenges, as it is a hardy shrub that can withstand various climates and conditions.
- Rejuvenation: The lush evergreen nature of this plant symbolizes renewal and the continuous cycle of life, reflecting the plant's capacity for growth and regeneration.
WaterThe Japanese Holly 'Ilex crenata' Dark Green prefers consistent moisture but does not like to be waterlogged. Water the plant deeply once a week, allowing the soil to dry slightly between waterings. During the growing season in spring and summer, you may need to water more frequently, especially if the weather is dry or hot. Aim to provide about 1 gallon of water for smaller shrubs and up to 2.5 gallons for larger ones each time you water. In the winter months, reduce watering as the plant's growth slows down.
LightJapanese Holly 'Ilex crenata' Dark Green thrives best in full sun to partial shade. Ideally, provide the plant with at least 4 to 6 hours of direct sunlight a day for optimal growth. However, it can also tolerate a spot that has dappled sunlight or light shade, particularly in the hotter parts of the day or in warmer climates.
TemperatureJapanese Holly 'Ilex crenata' Dark Green is hardy and adaptable to various temperature ranges. It can tolerate minimum temperatures down to about 0 degrees Fahrenheit but may suffer damage if temperatures drop lower. The ideal temperature range for this plant is between 50 to 80 degrees Fahrenheit for vigorous growth and health. It can handle the heat as long as it is not excessively hot; it's best to provide some afternoon shade if the temperatures regularly exceed 90 degrees Fahrenheit.
PruningPrune the Japanese Holly 'Ilex crenata' Dark Green to maintain its desired shape and size, and to remove any dead or diseased branches. Pruning is best done in late winter before new growth begins or in early summer after the new growth has hardened. You can prune up to a third of the plant's overall size each year if necessary, but light trimming is often sufficient.
CleaningAs needed
SoilThe Dwarf Japanese Holly, also known as Ilex crenata 'Dark Green', thrives best in a well-draining soil mix with a pH range of 5.5 to 6.5. Incorporate organic matter like compost and peat moss into the soil to maintain adequate moisture while ensuring proper drainage.
RepottingDwarf Japanese Holly should be repotted every 2 to 3 years to ensure continued growth and to refresh the soil. Younger, fast-growing plants may require more frequent repotting.
Humidity & MistingDwarf Japanese Holly prefers average humidity levels; however, it can tolerate a range from moderate to high humidity. Ensure proper ventilation to prevent fungal issues.
Suitable locationsIndoor
Place in bright, indirect light, ensure high humidity and well-draining soil for indoor growth.
Outdoor
Plant in well-drained soil, full sun to partial shade, and shelter from strong winds outdoors.
Hardiness zone
5-8 USDA
Life cycleIlex crenata 'Dark Green'® begins its life as a seed, germinating in favorable conditions with moist, well-drained soil and partial to full sunlight exposure. The seedling stage follows, where the plant starts to develop its root system and initial leaves. As it enters the juvenile phase, the shrub continues to grow at a moderate pace, producing its characteristic small, glossy, dark green leaves, and gaining height and width gradually. During this period it becomes more tolerant to pruning and begins to take shape for ornamental purposes. Upon reaching maturity, the shrub blooms with small, inconspicuous white flowers in late spring, which may later produce small black berries if pollination occurs and male and female plants are present. In its adult stage, Ilex crenata 'Dark Green'® requires regular maintenance, including watering and trimming to maintain shape, and can live for many years with proper care.
PropogationPropogation time
Early Spring
Ilex crenata Dark Green = 'Icoprins11' (PBR), commonly known as Japanese holly 'Dark Green', is typically propagated through cuttings. This is the most popular method because it ensures that the offspring will retain the same characteristics as the parent plant. To propagate through cuttings, a grower should select healthy, semi-ripe stems in late summer or early autumn. Cuttings of about 4 to 6 inches (10 to 15 cm) long should be snipped just below a leaf node, and the lower leaves should be removed. The cut end of the stem may be dipped in rooting hormone powder to increase the success rate. Then, the cuttings are inserted into a well-draining soil mix, ensuring a humid environment by covering with a plastic bag or placing in a propagator. After a few weeks to a couple of months, the cuttings should have rooted and can be transplanted to individual pots for further growth.
