Mexican orange (Choisya ternata) is a broadleaf evergreen shrub, native to southern North America, that produces attractive and fragrant white flowers. The palm-shaped leaves have three leaflets, and they produce a pleasant scent when crushed. White star-shaped flowers appear in three- to six-inch-long corymbs, mostly in the spring and early summer, and sometimes sporadically through the summer and into fall. The orange-scented flowers turn into a fruit that is neither showy nor edible composed of a leathery capsule with two to six sections.
Mexican orange is typically planted as a container-grown nursery plant in spring or fall. It is a fast-growing plant that can grow as much as two feet per year, but it accepts frequent pruning if you want to keep it more compact.
|Common Name||Mexican orange, Mexican orange blossom, Mexican orange flower, mock orange.|
|Botanical Name||Choisya ternata|
|Plant Type||Broadleaf evergreen shrub|
|Mature Size||4-8 ft. tall, 4–8 ft. wide|
|Sun Exposure||Full sun to partial shade|
|Soil Type||Fertile, well-drained|
|Soil pH||Slightly acidic|
|Hardiness Zones||7–10 (USDA)|
|Native Area||Southern North America, Mexico|
Mexican Orange Care
This shrub usually does well in any sunny location with fertile, well-draining soil. In regions with some winter frost, plant it in an area that is sheltered from harsh winter winds. Plant it in well-loosened soil at the same height it was growing in the nursery container. Mix in some fertilizer to the bottom of the planting hole to stimulate good root growth. Water well upon planting, then water at least weekly for the first few months. In winter, reduce watering.
This plant doesn't require pruning to maintain its health, but it also does not mind regular pruning to shape it and keep it compact.
A full sun to partial shade location is recommended for Mexican orange, but it will survive in full shade, as well. Shadier conditions will result in fewer flowers. Ideally, give it a spot with full sun in the morning, but with some protection from the hot afternoon sun.
This plant performs best in soil that is fertile and humusy, well-draining and slightly acidic. But it will not mind neutral or even slightly alkaline soils.
Keep this plant moist when first planted, watering deeply to help the shrub establish its root system. Once established, watering deeply but less frequently. A watering schedule that provides one inch of water per week (rainfall plus irrigation) is usually sufficient, though very hot weather might require more frequent watering. Spreading a layer of mulch will help retain soil moisture in summer.
Temperature and Humidity
Mexican orange is considered hardy in USDA zones 7 to 10, but it has been known to survive occasional temperature dips down to as low as 5 to 10 degrees Fahrenheit. However, reliable flowering requires an environment that never falls below 27 degrees. Ideal winter temperatures are 40 to 50 degrees.
Fertilize in the spring with compost or well-rotted manure. New plants will require extra phosphorus to develop a strong root system—this can be added to the bottom of the planting hole. In warmer climates, an extra fall fertilizer feeding is recommended.
Types of Mexican Orange Plant
A very popular variety is 'Sundance', the trademarked name for the C. ternata 'Lich' cultivar. It has striking golden foliage. It is hardy in zones 7 to 10 and grows 4 to 8 feet tall,
In addition, two hybrid plants are popular garden specimens:
- Choisya x dewitteana 'Aztec Pearl': This award-winner has pinkish-white flowers and grows to eight feet. It is hardy in USDA zones 8 to 10.
- Choisya x dewitteana 'Londaz' White Dazzler: This is a shorter, four- to five-foot shrub with especially dense white flowers.
Pruning is not required for the health of this shrub, but you can trim it to maintain the desired shape and size. Occasionally some leaves will experience dieback, and in those cases, cut back the plant—it will tolerate pruning all the way to the ground, if necessary. Some gardeners choose to prune the plant back after flowering to achieve a more formal appearance. This kind of light pruning immediately after the plant flowers often stimulates continued sporadic flowering through the summer and into early fall.
Propagating Mexican Orange Plant
Mexican orange can be grown from seed or propagated from semi-hardwood cuttings, but be aware that many varieties sold in garden centers are trademarked cultivars that cannot be legally propagated by any means. However, if you have a pure species plant or a non-trademarked cultivar, you can propagate your Mexican orange by rooting semi-hardwood cuttings. Here's how to do it:
- In mid to late summer, use sharp pruners to clip a six-inch semi-hardwood cutting (mature, but not yet fully hard).
- Remove the lower pair of leaves, retaining just one or two pairs of leaves at the top of the cutting.
- Dip the bottom of the cutting in powdered rooting hormone, and plant the cuttings in a porous seed starter mix (or a mixture of potting mix and sand).
- Place the cutting in a bright location but out of direct sunlight, and keep the potting medium just barely moist. Within a few weeks, the cutting will develop roots and new growth should begin.
- Move the rooted cutting outdoors and continue growing, repotting as necessary. It's best to grow the cutting for a full year before transplanting into the garden. In winter, protect your plant from cold—ideal winter temperatures are 40 to 50 degrees Fahrenheit.
How to Grow Mexican Orange Plant From Seed
Propagating Mexican orange from seed is slow and not always successful, so it is rarely done except by greenhouse professionals. If you want to try it, sow the tiny seeds from the fruits very shallow in seeding flats. Keep the seedling flats moist in bright greenhouse conditions (but out of direct sunlight) until they sprout. When large enough to handle, the seedlings can be transplanted into individual pots filled with potting mix. The seedlings are typically grown for a full year in a greenhouse (or indoors) before they are ready for outdoor pots or planting in the garden.
Potting and Repotting Mexican Orange Plant
In cooler regions of the country, a great option is to grow this shrub in a container that can be moved to a more sheltered location when the weather cool down. Choose a well-draining pot (any material will do) that is at least twice as large as the nursery container. Standard commercial potting mix works fine for container-grown shrubs. Mixing in some sand can help with drainage. This is a fast-growing shrub, so repotting will be necessary every few years.
When grown in pots, this species might be attacked by Pythium root rot, but is otherwise disease-free. Mexican orange grown in containers will need more frequent watering and feeding than garden-grown plants.
These shrubs require almost no extra care for winter other than offering a fall fertilizer feeding. Move potted plants to a spot that is sheltered from harsh, cold winds. If you live in a cold-winter zone, move your potted plant indoors to a sunny location.
Common Pests & Plant Diseases
Mexican orange is free of almost all plant diseases, but it can be susceptible to red spider mites (controlled with neem oil or another horticultural oil) and snails (which can be picked off or baited).
How to Get Mexican Orange to Bloom
Mexican orange typically blooms with large clusters of fragrant white flowers for several weeks in early or late summer. A light pruning immediately after they are finished flowering can stimulate sporadic additional flowers through the summer and into early fall. If the plant does not flower, it is usually for one of these reasons:
- Not enough sun: Although these plants tolerate partial shade, they need a full six hours of sunlight, preferably in the morning, to generate ample flowering.
- Pruning at the wrong time: Mexican orange blooms on old wood developed during the previous growing season, so if you prune it in winter or too early in the spring, you will be sacrificing the flower buds. If pruning is necessary, do it immediately after flowering, which provides plenty of time for the growth that will provide the next season's flowers.
- Bad timing for fertilizer: Mexican orange is best fed with compost in the spring, then a light feeding in the fall. Too much nitrogen in the spring will stimulate green growth at the expense of flowers.
- Poor soil: Mexican orange requires rich, humusy soil. If your plant is not blooming, make sure to blend in compost in the spring and feed with fertilizer it in the fall.
- Plants are too young. It can take as long as three years for a Mexican orange plant to mature into a flowering plant, especially if it is started from seed. If a potted nursery plant doesn't flower the first year, it might simply be a young plant that needs another season to mature.
How can I use this plant in the landscape?
The dense bushy growth of the Mexican orange, coupled with the glossy foliage, makes it a popular ornamental plant, either isolated in the landscape or included within large border gardens. Its tolerance for pruning makes it equally useful as a hedge or foundation shrub. In mixed gardens, it 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.
How long does a Mexican orange plant live?
While most small evergreen shrubs are somewhat short-lived, Mexican orange is an exception, often living many decades with little decline in appearance. This requires ideal growing conditions, however.
What about wildlife?
Mexican orange is extremely attractive to bees, butterflies, and other pollinators when it is in bloom. And fortunately, it is fairly resistant to damage from deer, rabbits, and other browsers.
“Choisya Ternata - Plant Finder.” Missouribotanicalgarden.org, https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=292058