How to Grow and Care for Mexican Orange Plant

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 3- to 6-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 add as much as 2 feet per year, but it accepts frequent pruning if you want to keep it more compact.

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 a hole with well-loosened soil at the same height it was growing in the nursery container. Add some fertilizer in the bottom of the hole to stimulate good root growth. Water well upon planting, then at least weekly for the first few months. In winter, watering should be reduced.

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.

Light

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.

Soil

This plant performs best in soil that is rich and humasy, well-draining and slightly acidic. But it will not mind neutral, or even slightly alkaline soils.

Water

Keep moist when first planted, watering deeply to help the shrub establish its root system. Once established, watering should still be deep, but less frequent. A watering schedule that provides 1 inch per week (rainfall plus irrigation) is usually sufficient, though very hot weather may require more frequent watering. Mulching the ground in summer can help retain soil moisture.

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 about 27 degrees. Ideal winter temperatures are 40 to 50 degrees.

Fertilizer

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, there are two hybrid plants that are popular garden specimens:

• Choisya x dewitteana 'Aztec Pearl': This award-winner has pinkish-white flowers and grows to 8 feet. It is hardy in zones 8 to 10.
• Choisya x dewitteana 'Londaz' White Dazzler: This is a shorter, 4- to 5-foot shrub with especially dense white flowers.

Pruning

Pruning is not required for the health of this shrub, but trimming can be performed to maintain the desired shape and size. Occasionally the shrub will experience dieback of many leaves, and in those cases, it should be cut back—it will tolerate pruning all the way back 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:

1. In mid to late summer, use sharp pruners to clip a 6-inch semi-hardwood cutting (mature, but not yet fully hard).
2. Remove the lower pair of leaves, retaining just one or two pairs of leaves at the top of the cutting.
3. Dip the bottom of the cutting in powdered rooting hormone, then plant the cuttings in a porous seed starter mix (or a mixture of potting mix and sand).
4. 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.
5. 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, the tiny seeds from the fruits can be sown shallowly 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 garden planting.

Potting and Repotting Mexican Orange Plant

In cooler options, a great option is to grow this shrub in a container that can be moved to a more sheltered location when the weather cools. 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 may be attacked by Pythium root rot, but is otherwise disease-free. Mexican orange flowers grown in containers will need more frequent watering and feeding.

Overwintering

These shrubs require almost no extra care for winter, other than offering a fall fertilizer feeding. Potted plants can be moved to a spot that is sheltered from harsh winds. If you live in a cold-winter zone, a potted plant can be moved 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 late summer or early 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 just compost in the spring, then a light feeding in the fall. Too much nitrogen in the spring will stimulate lots of 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 much 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 may simply be a young plant that needs another season to mature.