A native of the southern regions of North America through Mexico, there is little doubt how the Mexican orange came by its name. The attractive white flowers of this evergreen shrub not only produce a distinct orange scent but are similar in appearance to the blossoms found on the orange plant.
The dense bushy growth of the Mexican orange, coupled with the glossy foliage, makes it a popular ornamental plant. As an added bonus, the leaves are also fragrant. A popular cultivar of this species is ‘Sundance’, which produces bright golden yellow foliage on new shoots, turning yellow-green as the leaves mature.
Butterflies and honeybees are particularly fond of the flowers and abundant nectar produced by this shrub. Not surprisingly, both the standard Mexican orange and the cultivar ‘Sundance’ were given the prestigious Royal Horticultural Society (RHS) Award of Garden Merit.
The botanical name for the Mexican orange is Choisya ternata. The genus was named after a Swiss botanist, Jacques Denys Choisy.
Most commonly known as the Mexican orange, this species is also called the Mexican orange blossom, Mexican orange flower, and mock orange.
Preferred USDA Hardiness Zones
The preferred USDA zone for Mexican orange is zones seven to ten. It will tolerate a light frost to as much as 27° F (-2° C) as long as it has sufficient shelter.
Size and Shape
This shrub grows in a dense rounded shape that reaches six to eight feet in height and width. Initially, it is fast growing but slows over time. Maximum size is reached in 10 to 20 years.
A full sun to partial shade location is recommended for Mexican orange, but it will grow in full shade as well. It should be planted where it will be sheltered from strong winds, in soil that is moist and loamy, but well-drained.
Mexican orange is an evergreen with glossy foliage that remains dark green during all seasons. The leaves are arranged in a palmate fashion with three leaflets. When crushed, the leaves produce a pleasant fragrance that some compare to basil, while others describe it as citrusy. The ‘Sundance’ cultivar has golden colored foliage.
White star-shaped flowers appear in three to six inch long corymbs during the spring and often again in the autumn. The flowers produce a distinct orange scent, hence the name of Mexican orange. The fruit, that is neither showy nor edible, is composed of a leathery capsule having two to six sections.
Trellises are an ideal application for Mexican orange, or against walls. The dense grown of this shrub makes it ideal as a hedge plant, as a border, or as a foundation plant. A single Mexican orange also makes a great focal plant in a garden bed.
Another great option is to grow this shrub in a container which can be moved to more sheltered locations in cooler climates. Mexican orange is a good companion plant for California lilac, Geranium, Iris, and Shasta daisy. The glossy green foliage and cut flowers are often harvested for use in floral arrangements.
This species does not do well with the high nighttime heat that sometimes occurs during summer. Fertilize in the spring with compost or well-rotted manure. Mexican orange can be grown from seed or propagated from semi-hardwood cuttings.
New plants will require extra phosphorus to develop a strong root system. Keep moist when first planted. Once established watering should be deep, but less frequent.
Maintenance and Pruning
Little pruning is required but can be performed to maintain the desired shape and size. Occasionally the shrub will experience a dieback of many leaves, and in those cases should be cut back. Mexican orange will tolerate being cut back to the ground, if necessary. Some gardeners choose to prune the plant back after flowering to achieve a more formal appearance.
Pests and Diseases
Mexican orange is susceptible to a few pests that include glasshouse red spider mites and snails. When grown in pots, this species may be attacked by Pythium root rot, but is otherwise disease free.