Macadamia nut (Macadamia integrifolia)
Discover the Macadamia integrifolia, the prized Macadamia nut tree. A stunning broadleaf evergreen for USDA Zones 9-11.
Complete Plant Information
Overview
The Macadamia integrifolia, widely recognized as the source of the delicious Macadamia nut, is a magnificent broadleaf evergreen tree prized both for its edible bounty and its strong ornamental presence. This species commands attention in the landscape, growing into a large, spreading canopy that offers considerable shade. Its suitability for warmer climates makes it a specialist choice for subtropical and tropical gardening areas.
Native to Australian rainforests, this tree thrives under conditions that mimic its humid origins, requiring consistent moisture and protection from harsh conditions. While it carries a low maintenance level once established, its ultimate value comes from its consistent productivity, yielding the famously hard-shelled nuts central to global cuisine. Successful cultivation of the Macadamia integrifolia begins with understanding its specific soil and climatic requirements.
Gardeners looking for a substantial specimen tree that offers aesthetic appeal—including fragrant, showy spring flowers—alongside perennial fruit production will find the Macadamia integrifolia an excellent, long-term investment. It is the most commercially significant species of Macadamia, particularly prevalent in Hawaiian cultivation history.
Fast Facts
- Plant Family: Proteaceae
- Plant Type: Broadleaf evergreen
- Native Range: New South Wales
- Hardiness Zones: USDA Zones 9-11
- Size at Maturity:
- Height: 30-50 ft
- Spread: 20-40 ft
- Bloom Time: Seasonal bloomer
- Bloom Description: White to pinkish-white
- Sun Exposure: Full sun
- Water Needs: Medium to wet
- Maintenance Level: Low
How to Grow
Planting your Macadamia integrifolia should occur during warmer periods, avoiding the onset of frost which this species absolutely cannot tolerate. Select a site with rich, deep, well-drained soil, as the tree requires good drainage despite its preference for medium to wet moisture levels. Full sun exposure is essential for optimal flowering and nut production for this evergreen.
Established trees demand consistent rainfall, ideally at least 50 inches annually, though they show good drought tolerance once their root system is mature. If natural rainfall falters, maintain regular, deep watering, especially during fruit development periods. Culturally, it is crucial to place the Macadamia nut tree in locations sheltered from strong, damaging winds that can stress the canopy or damage developing nuts.
Maintenance is generally low, as few serious insect or disease problems affect this species. Fertilization should be balanced, focusing on essential micronutrients often lacking in subtropical soils. Pruning is minimal, usually restricted to removing dead or crossing wood to maintain an open structure suitable for light penetration.
Landscape Uses
The Macadamia integrifolia excels when utilized as a stately Shade Tree, providing broad, cooling cover over broad expanses of lawn or patio areas. Its dense, glossy foliage offers year-round visual interest, complementing its seasonal display of sweetly fragrant flowers that often appear in winter and spring.
Beyond its ornamental merit, the primary landscape application is commercial production of the highly sought-after Macadamia nut. Where space allows, planting several trees ensures better cross-pollination and maximizing nut harvest. Ornamentally, place the tree where its mature size (up to 50 feet tall with a 40-foot spread) can be accommodated, ensuring it does not crowd structures or underground utilities.
Standout Features
Flower Qualities
- Showy
Fruit Qualities
- Showy
- Edible
Noteworthy Characteristics
Macadamia integrifolia, commonly called macadamia nut, is a large, spreading broadleaf evergreen tree that typically grows to 30-50’ tall. It is native to rainforests in southeastern Queensland, Australia, though often associated with Hawaiian cultivation today. Glossy oblong-lanceolate leaves are usually arranged in whorls of three, creating dense coverage, followed by sweetly fragrant white to pinkish-white flowers which bloom in winter and spring before yielding the famously hard-shelled nut.
Tolerances
Potential Problems
Gardeners report that Macadamia integrifolia generally suffers from no serious insect or disease problems. The most significant threat remains environmental stress, particularly exposure to frost; ensure planting occurs only in USDA Zones 9 through 11 where chilling injury is unlikely. Overwatering leading to poor drainage is the most common cultural issue that can lead to root issues, so soil health is paramount.
Frequently Asked Questions
What hardiness zones is Macadamia nut suitable for?
The Macadamia nut tree is best grown where it is winter hardy, thriving in USDA Zones 9 through 11. Intolerance of frost means it needs protection in cooler microclimates within these zones.
How large does Macadamia integrifolia grow?
This species develops into a large tree, typically reaching heights between 30 and 50 feet tall, with a spread ranging from 20 to 40 feet wide, requiring ample space in the landscape.
What sun exposure does Macadamia integrifolia need?
For robust health and optimal nut production, the Macadamia integrifolia requires full sun exposure throughout the day.
When does Macadamia nut bloom?
The tree is a seasonal bloomer, producing sweetly fragrant flowers that are white to pinkish-white, generally blooming during the winter and spring periods.
Conclusion
The Macadamia integrifolia stands out as a dual-purpose specimen, offering high-value commodity production alongside the structural beauty of a mature shade tree. Understanding its need for excellent drainage and reliable moisture ensures the successful cultivation of the desirable Macadamia nut. Before planting, verify that your location falls firmly within USDA Zones 9-11 and plan for ample space to accommodate its mature spread.
Companion Planting
When establishing Macadamia integrifolia, consider companion plants that share its preference for rich, well-drained soils and consistent moisture without being overly aggressive competitors. Planting lower understory tropical or subtropical shrubs that thrive in partial dappled shade (once the Macadamia canopy develops) can create an attractive, layered look. Avoid plants with very shallow root systems directly competing at this tree’s base, favoring those established further out.
In areas where the intense full sun might be too dry for some neighbors, consider pairing the Macadamia nut tree with other large, evergreen subtropical fruits or nuts that require similar management practices, thus simplifying your maintenance routine without overcrowding the prime growing area for the main tree.
Design Ideas for the Broadleaf Evergreen
Utilizing the Macadamia integrifolia as a single specimen planting allows its impressive height and spread to define a large area, utilizing its role as a magnificent shade tree. In larger properties, groupings of three or five trees can create an informal grove, mimicking its native forest environment while maximizing harvest zones. The contrast between its deep green, glossy leaves and the delicate white-to-pinkish-white blooms in winter makes it excellent for brightening the cooler season landscape.
For properties requiring screening or property definition, two rows of Macadamia integrifolia can create a dense, durable hedge or windbreak, though initial spacing must account for their eventual 40-foot spread. Remember, its low maintenance level means it integrates well into larger, less intensively managed landscape environments once past its establishment phase.
