How To Grow And Care For The Mountain Mahogany (Cercocarpus spp.)

Mountain mahoganies are plants of the genus Cercocarpus. There are several mountain mahoganies that are native to the Western United States and Mexico that have the potential to make great garden plants, especially for those who enjoy gardening with native and wildlife attracting plants.

What Is A Mountain Mahogany

Although 9 or 10 mountain mahogany species are accepted, this article deals primarily with the true mountain mahogany, Cercocarpus montanus, and the curl-leaf mountain mahogany C. ledifolius.

The true mountain mahogany tree, also known as the alderleaf mountain mahogany, is a semi-evergreen shrub or small tree. These plants will shed a varying percentage of leaves in the winter, depending on rainfall and temperatures.

This plant usually grows as a multi-stemmed shrub with heights of 3-16 ft (1-5m) but may also take a single-stemmed tree form, occasionally reaching heights of 23ft (7m). One inch long, elliptical, and with serrated edges are the leaves of the most common species, the alder leaf mahogany.

In C. montanus, the leaf margins are complete from the petiole, becoming toothed towards the rounded tip. Oval leaves measure 0.4-2 inches (1-5cm) in length and 0.4-1 inch (1-2.5cm) across.The bark of this plant is smooth and gray-brown in color. (1)

The curl-leaf mountain mahogany is an evergreen species that generally grows as a small to medium-sized tree reaching heights of around 35ft (10.6m), although stunted populations are quite often found where plants don’t grow taller than about 3-7ft (1-2m).

Curl-leaf mountain mahoganies have elongated leaves which are pointed on either end. These measure 0.4-1.7 inches (14-20mm) in length and 0.1-0.4 inches (3-10mm) across. The bark of this species is thick, becoming deeply fissured with age. (2)

These plants are native to the USA and Mexico where they occur throughout much of the west and into the Mexican state of Baja California. They occur in a variety of habitats, from moist fertile sites to exposed rocky areas.

Cercocarpus Flowers

Mountain mahoganies typically begin to flower and fruit at an age of 5 to 15 years. The small white flowers have 5 sepals and no petals and are mildly scented. This plant usually flowers in winter and spring but may blossom from late March to early July.

While the flowers of these plants are not particularly impressive or showy, their fruits are certainly their most interesting and attractive feature. These mature from July into September and are wind-dispersed, which explains their interesting shape. The fruits of this plant are endowed with what could be described as a long (2-3 inches/ 5-7.5cm), fluffy tail (more accurately described as a plumose style) which acts to spread the fuzzy seeds widely on the breeze. (3)

How To Grow A Mountain Mahogany Plant

Mountain mahoganies can be grown from seed, or cuttings taken in spring. The viability of mountain mahogany seeds varies and generally, cold stratification is necessary before planting the seeds in late fall or winter. Seeds should be sown in a standard potting mix to a depth of around ¼ inches (6mm) and be kept moist until the seeds germinate. (4)

These plants from the rose family can be grown in a variety of soil types but show a preference for very well-drained substrates with soil pH values of 5-8. These are highly drought resistant plants with low water requirements. In nature, they grow in low rainfall areas and often very shallow, dry soils.

These plants should be planted in full sun for best results and are cold hardy down to at least USDA zone 6 and UK zone 5. Growth in C. montanus is moderate to fast while curl-leaf mahogany is a slow-growing species that may take as long as a century to reach its final size. These are extremely long-lived plants, with recorded lifespans of up to 1350 years!

Care And Maintenance

True mountain mahogany shrub is very hardy and low maintenance and grows quickly with minimal or no additional irrigation. Curl-leaf has similar qualities, although it will not grow at the same rate.

In order to survive in the often harsh conditions of their natural habitats, these plants are heat and drought tolerant, very handy features for dry and desert zone gardens.

Ecologically, these plants are well adapted to survive browsing by deer and other game, good indications that this species is very tolerant of pruning. However, their popularity with large game animals could be a problem if these are present in your neighborhood or property. Large animals do not kill the plants but definitely restrict their growth and result in a spiny and less tidy looking specimen.

Uses

Horticultural Uses

These small trees make great low-maintenance screens and can also be mass planted to create a water-wise hedge. Mountain mahoganies also have another practical landscaping use, they are effective for slope stabilization in erosion-prone areas.

Mountain mahoganies are a good choice for gardens in arid areas and are ideal for use in the northwest and southwest of the US as well as the Great Plains region.

Human Uses

The tough, red-colored wood of this plant was used traditionally for a number of purposes, especially as tool handles, spears, and arrow tips. Medicinally, this plant also had value in the treatment of stomach problems and coughing. (1)

Wildlife Uses

These plants are an important food source for deer, elk, and other large animals, something to consider if those animals forage in your area. In their natural habitat, these plants are a favorite habitat of Virginia’s warbler and various quail species. These plants are also the larval food source of the mountain mahogany hairstreak, a butterfly scientifically known as Satyrium tetra.

FAQs

How big are the leaves on mountain mahogany trees?

The leaves of mountain mahogany trees (Cercocarpus) vary in size depending on the species and environmental conditions. Generally, they are small, narrow, and elongated, typically measuring 1-3 inches in length.

How dense is mountain mahogany?

Mountain mahogany trees tend to have a dense and compact growth habit, with branches often growing close together. This dense foliage provides good cover and habitat for wildlife and helps the tree withstand harsh environmental conditions.

Where does mahogany grow best?

Mahogany trees (Swietenia) typically grow best in tropical or subtropical regions with rich, well-draining soil and plenty of sunlight. They are native to regions such as Central and South America, where they thrive in warm, humid climates.

What is the best climate to grow mahogany trees?

The best climate to grow mahogany trees is a tropical or subtropical climate characterized by warm temperatures, ample sunlight, and consistent rainfall. While they can tolerate a range of environmental conditions, they perform best in regions with long growing seasons and minimal frost or cold temperatures.

Conclusion

Mountain mahoganies are another great plant for the native, water-wise garden. Their low maintenance and watering requirements, coupled with wildlife-attracting qualities make them great a choice for the eco-conscious gardener, especially in drier areas. If you have deer around, however, you should be prepared to share your plants with some hungry hairy herbivores!

For more shrubs to grow, check this page.

References

References