Osmanthus
( os - MAN - thus )
At-A-Glance Information
This genus of evergreen shrubs, commonly called Devilwood, needs full sun to partial shade and little to regular water. All species have handsome foliage and inconspicuous but fragrant flowers. They can be grown as shrubs or shaped into trees, and also make good informal or lightly clipped tall hedges. Osmanthus shrubs are native to eastern Asia and the Middle East. These shrubs are popularly used in parks and home gardens and are perfect additions to native plant gardens and naturalized landscapes. The blooms provide an essential food source for pollinators like bees and butterflies, and the fruit is a favorite of birds and other wildlife.
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osmanthus Species and Varietals
The genus Osmanthus contains about 30 species, and is a member of the plant family Oleaceae. The genus name is derived from the Greek words osma (meaning smell or fragrance) and anthos (meaning flower). Osmanthus growing zones vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.
Osmanthus delavayi (Delavay Osmanthus) This species grows well in zones 4-9 and 14-21 and is native to China. It reaches 4-6 feet tall and 6-8 feet wide, with dark green leaves that have toothed edges. Flowers bloom in springtime; this species has the largest flowers of any Osmanthus. This shrub is attractive year-round, and is great for planting around foundations or on retaining walls. Needs partial shade in warm summer areas. |
Osmanthus x fortunei This hybrid species is best in zones 4-10 and 14-24, and is a cross between Osmanthus heterophyllus and Osmanthus fragrans. It slowly reaches 15-20 feet tall and 6-8 feet wide, with holly-like green leaves and flowers that pop in spring and summer. Variety 'San Jose' (pictured) has fall flowers that range in color from orange to cream. |
Osmanthus fragrans (Sweet Olive) This species of Osmanthus grows well in zones 5-9, 12-24 and H1. It is native to China, Japan and the Himalayan region. It has a broad, dense, compact habit and reaches 10 feet tall and 6-8 feet wide. Medium green leaves are ovular and glossy, and flowers have a strong scent of apricot. Blooms heavily in spring and summer, and sporadically throughout the rest if the year. Can be trained as an espalier. Needs afternoon shade in warmer climates. |
Osmanthus heterophyllus (Osmanthus ilicifolius) (Holly-Leaf Osmanthus)
This species grows well in zones 4-10 and 14-25 and is native to Japan. Reaches 10-20 feet tall and a little wider, with spiny edged green leaves. Leaves look similar to Holly (however, they are arranged opposite rather than alternate on branches). Fall and winter flowers. Great as a hedge. This species is less frost tolerant than others. Choice varieties are listed and described below.
This species grows well in zones 4-10 and 14-25 and is native to Japan. Reaches 10-20 feet tall and a little wider, with spiny edged green leaves. Leaves look similar to Holly (however, they are arranged opposite rather than alternate on branches). Fall and winter flowers. Great as a hedge. This species is less frost tolerant than others. Choice varieties are listed and described below.
Caring for and pruning osmanthus shrubs
These shrubs prefer full to partial sun (at least 4-6 hours of sun each day). Some varieties listed above can take more shade; check the descriptions above for more information. The more shade these shrubs receive, the less flowers they will produce. They prefer well-draining soil with good organic content, and thrive in slightly acidic to neutral soil (with a pH of between 5.0 and 7.5). Keep the soil consistently moist, especially during the first year after planting. Once mature, these shrubs are considered to be relatively drought tolerant, withstanding short periods of no water. Water deeply when the top inch or two of soil feels dry to the touch. Lay down a 2-3 inch layer of mulch around the base of the plant; this will help with soil moisture retention.
Fertilizing should occur in springtime, though in many cases if the soil has been amended with organic material, it may not be needed. Feed with a balanced, slow-release fertilizer. Avoid over-fertilizing these plants, as this can cause the plant to put too much energy towards foliar growth and not enough towards flower production. Pinch tips of new plants to encourage a more bushy habit, and occasionally cut back wayward, dead or dying branches on mature plants. Prune as needed to shape after flowering has faded for the year. These shrubs have a dense growth habit, and can be trimmed into hedges and topiaries if desired.
Fertilizing should occur in springtime, though in many cases if the soil has been amended with organic material, it may not be needed. Feed with a balanced, slow-release fertilizer. Avoid over-fertilizing these plants, as this can cause the plant to put too much energy towards foliar growth and not enough towards flower production. Pinch tips of new plants to encourage a more bushy habit, and occasionally cut back wayward, dead or dying branches on mature plants. Prune as needed to shape after flowering has faded for the year. These shrubs have a dense growth habit, and can be trimmed into hedges and topiaries if desired.
Propagation
Propagating Osmanthus by Cutting
- Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
- In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
- Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
- Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.
Problems and Pests
Osmanthus shrubs are generally resistant to pests and disease.
Gallery
Videos
All about these wonderful shrubs.
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A great introductory video to these shrubs.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 466, Osmanthus
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