What is Eucalyptus deglupta or Rainbow Eucalyptus?
Eucalyptus deglupta, commonly known as Rainbow Eucalyptus, is undoubtedly one of the most unique and spectacular trees in the plant world. It stands out mainly for its incredible coloration of its trunk, a characteristic that makes it a true piece of living art in any environment where it's grown. Its multicolored bark can display shades of green, blue, orange, purple, brown, and reddish, creating the striking rainbow effect it's famous for.
In addition to its appearance, Eucalyptus deglupta differs from the rest of the eucalyptus trees in that It does not give off the typical intense aroma from other members of the genus, making it attractive to those seeking a striking tree without the characteristic fragrance of the classic eucalyptus.
Origin and Distribution of the Rainbow Eucalyptus
Eucalyptus deglupta is native to tropical areas of Southeast Asia, being native to places such as New Britain, New Guinea, Seram, Sulawesi and Mindanao. It is the the only eucalyptus that grows naturally in the northern hemisphereIts natural habitat includes humid lowland tropical rainforests, where rainfall is abundant and the climate is warm year-round.
Thanks to its ornamental value and adaptability, it has long been cultivated in other tropical and subtropical regions around the world. Today, Eucalyptus deglupta specimens can be found in botanical gardens, public parks, and private gardens in countries with warm, humid climates, where it can reach its full aesthetic and shade potential.
Botanical Description and Characteristics
The Rainbow Eucalyptus is a large tree. When grown in optimal conditions, it can easily outgrow the Meters 70 in its natural habitat, although in cultivation its size is usually somewhat smaller. The trunk is generally straight, of considerable diameter and with a smooth bark that peels off in thin, elongated strips. The process of bark peeling It reveals newly exposed internal layers, which are initially deep green and then, upon exposure to light and air, acquire shades of blue, orange, purple, brown, or reddish. This process occurs in a gradual and continuous manner, giving rise to the characteristic colorful mosaic that decorates its trunk.
Sheets: The leaves of Eucalyptus deglupta vary greatly between their juvenile and adult stages. In their juvenile stages, the leaves are large, opposite or sub-opposite, oval to lanceolate, measuring between 10 and 12 centimeters long and about 4 to 6 centimeters wide, with a twisted, light green petiole. When the tree matures, its leaves become alternate, somewhat narrower and elongated, while maintaining their deep green color. They are evergreen, so the tree retains its foliage year-round.
Flowers and fruits: The Rainbow Eucalyptus blooms in axillary or terminal clusters with creamy white flowers. Each inflorescence can bear six to eight flowers per umbel. After pollination, fruits form in the form of cup-shaped capsules (small cups) containing winged seeds. These capsules are approximately half a centimeter long and usually split open into four valves, releasing the seeds.
Root system: The roots of Eucalyptus deglupta are primarily radial, lateral, and superficial. They typically reach a length equivalent to between a quarter and a third of the tree's height. This root system, although vigorous, does not usually pose a threat to sidewalks or foundations, but its size should be considered when choosing a planting site.
Multicolored Bark: Why Does the Trunk Have So Many Colors?
La main feature What distinguishes Eucalyptus deglupta from all other trees is the multi-colored phenomenon of its trunk. This phenomenon originates when the outer bark peels off in different areas of the trunk and branches, leaving an inner layer of bright green color exposed. Over the weeks, this bark oxidizes and gradually becomes colored blue, purple, orange, reddish and brownSince not all the bark sheds at the same time, the trunk always displays a mixture of colors, with the colors changing as each area ages and is exposed to the atmosphere.
This process is continuous throughout the year in favorable climates, as the plant has no defined dormancy period. Thus, the Rainbow Eucalyptus is one of the few trees whose appearance can change radically from month to month, always surprising with the vividness and variety of colors in its bark.
This spectacular feature has made it an excellent focal element in landscape design.
Uses and Benefits of Eucalyptus deglupta
Although the ornamental use This is what has made the Rainbow Eucalyptus popular in gardens and parks in warm climates, this tree also has industrial and ecological applications:
- Paper production: Its wood is highly valued in the production of high-quality white cellulose, as the chemical structure of the fibers is especially suitable for this use.
- Carpentry: The wood of Eucalyptus deglupta is also used in construction and light carpentry, although its main purpose is the paper industry. It is a fast-growing wood with high renewable potential.
- Natural repellency: Some parts of the tree present antimicrobial and insect repellent properties, which contributes to the health of the environment where it develops.
- Ecological value: Its rapid growth makes it a useful species for soil protection and reforestation in humid climates, although in regions outside its natural range it should be planted responsibly, avoiding affecting local biodiversity.
Furthermore, Rainbow Eucalyptus is not considered toxic to pets or people, although the essential oil contained in its leaves can be irritating if ingested in large quantities.
Environmental Requirements and Conditions for Cultivation
Eucalyptus deglupta is a demanding species in terms of temperature and humidity, so its optimal cultivation occurs in:
- Climate: Prefer humid tropical or subtropical climates, with mild to warm temperatures year-round and no frost. It is very sensitive to cold and can suffer irreversible damage from moderate frosts.
- Solar exposition: Always choose one sunny location; it requires many hours of direct sunlight to develop its full potential and show the full intensity of its bark color. In partial shade or shady locations, its growth will be slower and less attractive.
- Ground: It tolerates a wide range of soils, although prefers deep-textured, fresh, moderately fertile and well-drained soilsSlightly acidic soils enhance its growth, but it can adapt to sandy and poor soils with somewhat slower growth. It can tolerate a certain degree of salinity in the substrate, allowing it to grow near coastal areas.
- Humidity: This tree needs constant humidity in the soil, especially in its first years of life. If the environment is too dry or has low humidity, growth slows and the bark's color may be affected. In warm areas with dry summers, watering should be abundant and very regular.
- Wind: Avoid planting Rainbow Eucalyptus in locations exposed to strong winds, as its branches can be fragile, especially during the first years of development.
How to Plant Eucalyptus deglupta
- Choice of place: Select a very sunny, spacious area away from buildings to avoid problems with the size and root development of the adult tree.
- Soil preparation: Make sure the soil is well-drained and deep. If the soil is compact or infertile, it's advisable to improve it with organic matter and perlite to ensure rapid establishment and vigorous growth.
- Plantation: It can be used as a single tree or in groups to create small ornamental forests. Its visual spectacularity is especially appreciated when planted as a single specimen in large gardens.
- Spacing: Leave a minimum separation of 12 meters between individuals and from buildings or roads, to avoid future problems with size and root system.
Essential Care of Rainbow Eucalyptus
- Irrigation: During the first few years, it is essential to keep the substrate constantly moist, avoiding waterlogging. Ideally, water frequently and thoroughly, especially during hot, dry periods. Once the tree is established, it can tolerate short periods of drought, although always prefers a certain humidity in the soil.
- Fertilization: A balanced fertilizer application during the growing season promotes growth. In poor soils, fertilizing several times a year is especially recommended.
- Pruning: During the first few years, pruning is limited to shaping the tree and removing damaged or diseased branches. Light formative pruning helps maintain its upright structure. Afterward, only minimal maintenance is required to remove dead branches.
- Plagues and diseases: Eucalyptus deglupta is quite rustic and resistantThe main threats are usually adult wood borers, snails, and slugs on seedlings, and, in regions where termites are present, they can affect young plants. In general, pests are rare if humidity and light conditions are adequate. It is recommended to treat with specific products if damage is detected.
- Tutoring: It is recommended to place stakes during the first two years after planting to prevent the tree from growing lean or suffering wind damage.
- Protection against the cold: Given their sensitivity to low temperatures, it is important to protect young specimens from possible frost by using covers or mulch.
Reproduction of Eucalyptus deglupta
La multiplication Rainbow Eucalyptus cultivation is carried out almost exclusively from seeds. The process is simple and effective if you follow these basic recommendations:
- Seed extraction: They are extracted from the mature capsules, which typically contain between 10 and 50 tiny seeds each. One gram of seeds can contain up to 18.000.
- Viability: Only a small proportion (around 10-12%) of the seeds usually germinate, so it is recommended to sow a larger number to ensure successful propagation.
- Sowing: The seeds should not be buried, but spread over the surface of a light, well-drained substrate, keeping it constantly moist. A peat substrate with perlite is ideal for ensuring good aeration and moisture retention.
- Germination temperature: Germination is optimal at around 24-28°C. If these conditions are maintained, the seeds will germinate in 8 to 15 days without the need for prior treatment.
- Pricking out and transplanting: When the seedlings have more than 3 or 4 true leaves and reach a manageable size, they can be transplanted into individual pots or grow bags. At this stage, it's best to keep them in semi-shade until the roots are well established.
- Getting used to the outdoors: Once the plants are well rooted and have grown sufficiently, they can be placed in full sun and continued with regular watering. If the climate is favorable, they will be ready to be transplanted to their final location in the garden or park in just one year.
Growth and Development: Rhythm and Aspects to Consider
Eucalyptus deglupta stands out within the genus for its enormous growth rateUnder optimal conditions, it can grow between 2 and 3 meters per year during its youth, even reaching 5 meters per year in areas with high rainfall and consistently warm temperatures. This growth rate, however, progressively decreases as the tree matures and stabilizes in height.
The tree can flower as early as 3 to 4 years old, even when still young. Flowering can occur for several months throughout the year, depending on climatic conditions and available light intensity. After flowering, the seed capsules mature for several months before splitting open.
Animal Compatibility and Toxicity
Eucalyptus deglupta It is not considered a toxic plant Not suitable for pets or humans, as long as large amounts of plant material are not ingested. However, as with other eucalyptus trees, the essential oil from its leaves can be a digestive irritant if consumed in excess. It is recommended that direct consumption by pets or small children be avoided.
Common Problems and Pests
Although it is a robust tree, some pests y enfermedades may affect you:
- Wood borers: They can cause considerable damage to adult specimens if not controlled in time.
- Snails and slugs: They mainly attack seedlings and young specimens, especially in humid environments.
- Termites: They only represent a danger in those places where they are naturally present in the environment.
- Diseases: They are rarely affected by serious diseases if kept in an environment with adequate light and humidity. In rare cases, root fungus may appear if the substrate remains waterlogged.
Pest control is usually achieved with insecticides or specific baits. Maintaining good ventilation, avoiding excess humidity, and removing plant debris are the best prevention measures.
Curiosities and Ornamental Value
In addition to its industrial use , as a ornamental treeThe Rainbow Eucalyptus is admired by landscapers and collectors of exotic species. Its colorful trunk makes it a centerpiece in tropical and subtropical gardens, adding variety and beauty to any plant arrangement. It is a preferred choice in public parks in many warm-weather cities and on major avenues in countries like the Philippines, where, in addition to its ornamental use, it is used for reforestation and slope protection.
Taxonomy and Nomenclature
- Kingdom: Plant
- Division: Angiosperms
- Class: eudicots
- Order: myrtales
- Family: myrtaceae
- Gender: Eucalyptus
- Species: Eucalyptus deglupta (also known by synonyms such as Eucalyptus binacag, Eucalyptus multiflora, Eucalyptus naudiniana, Eucalyptus sarassa, Eucalyptus versicolor, Eugenia binacag)
In different languages and regions, it is also known as Mindanao Eucalyptus o Philippine Eucalyptus, and is appreciated in Asia, America and Oceania.
Practical Tips for Growing in Private Gardens
- Location: Try to plant it away from buildings, pipes, or infrastructure, given its large size and rapid growth.
- Compatibility: Although its root system is not usually invasive to foundations, it does require space for proper development.
- Selection of specimens: If it is for small gardens, consider other smaller eucalyptus species, since the Eucalyptus deglupta not suitable for small spaces.
- Maintenance: Once well established, the tree will require less and less care, becoming a focal point of the garden for decades.
