How to Grow and Care for Fragrant Tea Olive (Sweet Osmanthus)

Osmanthus fragrans is an evergreen broadleaf shrub or small tree that is known by many common names, most of which allude to its powerful fragrance: fragrant tea olive, sweet osmanthus, sweet olive, fragrant olive. Long grown as a large indoor plant, fragrant tea olive is increasingly popular as an outdoor garden plant in warmer climates, USDA zones 8 to 11. It is a dense, multi-stemmed plant with elongated dark green leathery leaves, producing small but extremely fragrant white flowers in spring, with sometimes a smaller secondary bloom period in fall. In some regions, however, the principal bloom period is fall, and the plant has even been known to bloom sporadically year-round.

Like other tea olives, fragrant tea olive is generally planted as a nursery-grown container plant in fall, which allows it to slowly develop a good root system over the cooler months of winter. Fragrant tea olive has a fairly slow growth rate, adding 4 to 12 inches per year, occasionally more in warm coastal regions. Once established, it is an extremely long-lived plant.

Fragrant Tea Olive Care

Fragrant tea olive, as well as the other species in the Osmanthus genus, are excellent landscape plants for the southern U.S. and are sometimes grown as large potted houseplants in colder regions. They are resistant to most pests and diseases, and they don't mind heavy pruning. These plants like plenty of space, as some varieties can grow to 30 feet tall if conditions are right.

This plant likes lots of sun, although some afternoon shade will help prevent leaf scorch in hot southern regions. Fragrant tea olive grows best in moist, well-drained soil, but will readily tolerate even dense clay soils. Pruning is not necessary, as the plant naturally assumed a pleasant rounded shape, but fragrant tea olive also accepts the hard pruning necessary for using the plant in hedge applications or to control its size for container culture.

Light

Plant fragrant tea olive in full sun. Offer partial afternoon shade in climates with very hot summers.

Soil

Fragrant tea olive will grow easily in any good garden soil, but an average, moist, well-drained soil is best. These plants prefer an acidic to neutral soil (pH 5.0 to 7.5).

Water

Fragrant tea olive has average watering needs. Watering established plants is necessary only when there is no weekly rainfall. Fragrant tea olive is somewhat drought-tolerant once established, but don't expect it to thrive during extended droughts unless you water. Young plants should be regularly watered for the first year or so.

Temperature and Humidity

These plants are typically winter hardy to about 10 degrees Fahrenheit, provided temperature drops are gradual. But it can be damaged if temps fall too quickly from warm conditions to 20 degrees or so. It is rated as hardy in USDA zones 8 to 11. This plant does well in humid regions.

Fertilizing

Tea olives can benefit from a single spring feeding with a time-release shrub and tree fertilizer, ideally containing sulfur or iron. Never feed a tea olive immediately before cooler winter weather begins, as new growth stimulated by feeding can be damaged by frost. The exception is potted plants being moved inside for the winter—these do benefit from a light feeding as they move indoors.

Types of Fragrant Tea Olive

This plant is indeed a member of the olive (Oleaceae) family, and it has a delightful scent that is said to resemble jasmine, orange blossoms, ripe peaches, or apricots. O. fragrans is one of several species within the genus, known collectively as tea olives.

Fragrant tea olive (Osmanthus fragrans) is often planted in its native species form, which has creamy white flowers, but there are also naturally occurring forms and variations that are popular, including:

• Osmanthus fragrans f. aurantiacus is an orange-flowering form that often flowers in fall.
• Osmanthus fragrans var. thunbergii (also known as silver osmanthus) is a yellow flowering variation.
• Osmanthus fragrans va. semperflorens is an extremely hardy variation, surviving temps as low as minus 15 degrees Fahrenheit (zone 5). It produces continual flowers.

In addition, there are a number of named cultivars that have most attributes of the native species, but with flower color variations:

• 'Apricot Gold' produces apricot-gold flowers that are exceedingly fragrant.
• 'Butter Yellow' has bright yellow flowers.
• 'Conger Yellow' has yellow flowers, with leaves that are somewhat more showy than the species form.
• 'Fudingzhu' will flower for as much as nine months, with creamy-white flowers.
• 'Orange Supreme' has bright orange blossoms.

Finally, it is worth considering some of the other Osmanthus species, several of which make for excellent landscape plants with care needs that are similar to O. fragrans:

• Osmanthus americanus is a North American native species found in the maritime forests of the Southeast U.S. It is the only species of tea olive that tolerates salt spray, making it ideal for coastal locations. It is a good choice for gardeners who prefer a native plant, though its flowers are less showy.
• Osmanthus heterophyllus is known as "false holly" due to its glossy pointed leaves. This plant blooms in late fall and can reach a height of 15 feet. There are many named cultivars of this popular plant, many of which are hardy to zone 6. Some cultivars have variegated foliage.

There is also a popular hybrid form, Osmanthus x fortunei, which is a cross between O. fragrans and O. heterophyllus, combining the traits of both—toothed, holly-like leaves as well as fragrant flowers.

Pruning

Osmanthus plants only need pruning if they get too big or develop unattractive or dead branches. But fragrant tea olive, like other species of the genus, can be trained as a small tree, shrub, or espalier, and it can be used in hedges. Clip its tips to encourage growth and maintain the desired size. Make cuts 1/4 to 1/2 inch above a lower branch junction. 

Prune at the end of winter before buds appear. If you choose to prune, be careful not to overdo it, as too much pruning can prevent the plant from blooming. It can sometimes take as much as two years for the plant to resume good flowering after a hard, poorly-timed pruning.

Propagating Fragrant Tea Olive

Tea olives are generally most often propagated by stem cuttings taken in the late spring or early summer. Here's how to do it:

1. Prepare a mixture of sand and potting mix in a 1-gallon nursery container.
2. Use clean, sharp pruning shears to snip semi-hardwood cuttings that are about 8 inches long, then remove the bottom leaves.
3. Dip the bottom of the cutting in rooting hormone, then plant it in the sandy rooting medium.
4. Place in a bright outdoor location (but out of direct sunlight) and keep moist until roots develop. This can be a lengthy process, requiring as much as three or four months.
5. When roots are well developed and new growth has started, the plant is ready to be transplanted. With luck, a cutting taken in spring may be ready to plant by late fall or early winter, but it's not uncommon to grow it indoors or in a sheltered outdoor location until the following spring.

How to Grow Fragrant Tea Olive From Seed

It is possible, though not easy, to grow fragrant tea olive from seeds. It can take several months for the seeds to even germinate, and as much as a year before a seedling is large enough to transplant into the garden. But if you want to try it, collect some seeds from the ripened drupes (they are fully ripe about six months after flowering.)

Fill a small container with commercial seed-starter mix, then sow the seeds 1 to 11/2 inches deep and moisten the mix. Keep the pot in a warm, humid environment (generally indoors) until germination occurs, which can take as little as one week or as much as three months. Most growers find that it works best to keep the seed pot on a heat mat that is constantly on, and under grow lights that provide 14 hours of artificial light daily. The seed starter mix should be misted frequently to keep it moist.

After the seeds sprout and the seedlings develop true leaves, carefully transplant them into individual pots filled with standard potting mix. Keep the potted seedlings growing in warm, bright conditions until spring planting time, May or June.

Potting and Repotting Fragrant Tea Olive

Fragrant tea olives, as well as other species of Osmanthus, are often grown as potted plants in regions where they are not hardy. They can even be grown as houseplants, though they will require frequent tip-pruning to keep the plants at a manageable size. It's quite common to grow a fragrant tea olive in a large pot filled with standard peat-based potting mix, moving it indoors for the winter, then back outdoors during the warm spring and summer months. A heavy clay or ceramic pot is recommended to prevent tipping; make sure the container has good drainage.

When grown indoors, a fragrant tea olive plant will need a very bright location with plenty of sun, and make sure to keep it away from heat ducts. These plants may struggle if grown indoors all year. It's best to make sure they get a minimum of several weeks outdoors in a sunny location during the spring and summer.

Overwintering

No winter cold protection is necessary for these plants, provided you are growing them in the established hardiness range (zones 8 to 11). Fragrant tea olive is the most cold-hardy of the Osmanthus species, and even zone 7 gardeners may be able to grow them successfully in sheltered locations. Young shrubs may benefit from a cage of hardware cloth to protect them against gnawing creatures such as rabbits.

Potted shrubs should be moved indoors for the winter if you live in a region where nighttime temperatures will drop below 40 degrees Fahrenheit; you don't want to risk frost damage. Potted tea olives being moved indoors will benefit from a top-dressing of time-release fertilizer to keep them growing. But with outdoor garden shrubs, withhold feeding for the winter.

Common Pests and Plant Diseases

The only serious pest problems with fragrant tea olive are scale and aphids, which can be especially troublesome with plants moved indoors for the winter. Treat by spraying with horticultural oil.

Botryosphaeria canker can affect these plants, especially those that are stressed by drought. Cercospora leaf spot and anthracnose may occasionally occur. Phytophthora and Pythium root rots are sometimes seen in poorly drained or excessively wet soil.

How to Get Fragrant Tea Olive to Bloom

Fragrant tree olive usually will display flowers for around two months in spring and summer, but it's quite common for them to bloom intermittently at other times, even through the winter. In some regions, fall is the principal bloom period. Blooms are generally assured if the plant is getting plenty of sun and hasn't been nipped by frost that kills the flower buds.

• A potted tea olive that moved outdoors too early and gets touched by spring frost may not bloom for a full year.
• Untimely pruning that clips off the flower buds can also prevent blooms until the following season. The best time to prune is after the main flowering period is over, but before spring growth has begun.
• A single spring feeding with a slow-release fertilizer can also help ensure blossoms.
  
  

Common Problems With Fragrant Tea Olive

There are few common complaints with fragrant tea olive, but the plant can be sensitive to cold, and unexpected cold snaps can damage the flower buds for the following year, and even stunt the plant's growth for a full year or two.

Another common problem is that fragrant tree olives can drop their leaves unexpectedly. This most often occurs with potted plants grown indoors, but it's also possible with outdoor garden plants. Likely causes of leaf drop:

• Not enough water: These plants need moisture, and dry indoor winter air may cause desiccation that causes the leaves to drop. Indoor potted plants may well need daily light watering during dry winter months.
• Extreme temperature swings: This can happen during the transition period as potted plants are moved from outdoor to indoor locations, or indoors to outdoors. Treat potted tea olives as you would seedlings, "hardening them off" by gradually acclimating them to new conditions.
• Too little light: Again, this is more likely with potted plants moved indoors, where it can be hard to find a sunny winter location. Potted tea olives will need the brightest window you can find—or will need artificial light. Outdoor plants that drop leaves may be signaling that they are in a spot that's too shady.
• Pest and disease problems: Unhealthy tea olives often drop their leaves, so make sure your plant is not struggling with scale or fungal disease.