Styrax

( STYE - racks )

At-A-Glance Information

This genus of deciduous trees and shrubs, commonly called Storax or Snowbell, includes species which need full sun to partial shade and regular water to perform well in the landscape. In spring, they produce impressive shows of white or pink fragrant bell-shaped flowers. These plants are native to warm temperate regions of the Northern Hemisphere. Use these trees as focal points or specimens, in shrubberies or mixed large beds, or as street trees. They are commonly included in woodland, urban, small-space, and patio gardens. Take care when planting these shrubs and trees in the landscape, as plant parts are toxic to humans and pets.

Styrax Species and Varietals

The genus Styrax includes around 130 species of small trees and large shrubs, and is a member of the plant family Styracaceae. The plants in this genus are closely related to those in Halesia (Silverbell) and Pterostyrax (Epaulette Tree). Styrax growing zones are USDA hardiness zones 5-8 or Sunset climate zones 4-9 and 14-21. To find your zone, click here: Zone Map.

Styrax americanus (American Snowball, Mock-Orange, American Storax, American Silverbells, Snowbell Bush)
These plants are native to the southeastern United States, where they grow in habitats like wet swamp forests, wooded floodplains and stream banks. The species forms a shrub or small tree to 6 to 15 feet tall at maturity. Foliage is green and flowers are small and white.

Styrax benzoin (Gum Benjamin Tree, Loban, Kemenyan, Onycha, Sumatra Benzoin Tree, Sambrani, Kak~ku-ka.byæÑ:, Kamyan Thai, กำยานไทย, Kamyan Sumatra, กำยานสุมาตรา, Siam Benzoin, Kam Nhan, Cây Bồ đề, Bantung, Talanan)
These trees are native to India, Thailand, Myanmar, Cambodia, Laos, Vietnam, Malaysia, Borneo, and Indonesia and reach up to between 40 and 100 feet tall when mature. Resin from these trees is harvested, and is called Benzoin or Sambrani, used in incense, as flavoring, and as a medicinal tincture. These trees are cultivated as crop trees for their resin, but are also grown as ornamental shade trees, mainly in western Africa.

Styrax grandifolius (Bigleaf Snowball, Bigleaf Storax, Coast Snowbell, Large Leaf Storax, Storax)
These plants are native to the southeastern United States, and have larger leaves than most other species in the genus. The species forms a deciduous shrub or multi-trunked tree up to 20 feet tall at maturity. Bark is dark and streaky, and foliage is green with whitish-grey undersides.

Styrax japonicus (Japanese Snowdrop Tree, Japanese Snowbell, Egonoki)
This species is a tree native to eastern Asia that tops out around 30 feet tall and spreads to 30 feet or more at maturity. Trunk is slender and graceful, and the tree has a broad, flat top. Leaves are green and scalloped, and turn red and yellow in fall. Flowers form in small clusters that hang down from branches. Great tree to plant over a relaxation area; it is a great tree to look up into.

'Carillon' ('Pendula')
Shrubby habit with weeping branches.

'Emerald Pagoda'
Large dark green leathery leaves and 1-inch flowers.

'Evening Light'
With dark purple-maroon foliage and pink blooms.

'Nightfall'
With a weeping habit and dark purple foliage.

'Pink Chimes'
Shrubby but upright form with pink flowers.

'Snow Charm'
Rounded form, to 20 feet tall and just as wide.

'Snowcone'
Pyramid-shaped tree to 25 feet tall and 20 feet wide.

'Spring Showers'
Conical form with late bud break.

Styrax obassia (Styrax obassis) (Fragrant Snowbell, Big Leaf Snowbell, Bigleaf Snowbell, Big-Leafed Storax)
This species is a tree native to Japan, Korea, China, and eastern Russia that reaches 20-30 feet tall and about 2/3 as wide at maturity. Leaves are deep green and round, and turn yellow in fall. White flowers bloom in clusters in springtime. These small trees do very well against evergreen backdrops or in small or patio gardens.

Caring for styrax

Take care when planting these shrubs and trees in the landscape, as plant parts are toxic to humans and pets. These trees and shrubs prefer a spot in the landscape that receives full sun to partial shade. At minimum, they should be receiving between 4 and 6 hours of direct sun each day for optimal flowering and leafout. In hotter climates, these trees (especially when young) may appreciate some reprieve from direct sun in the warmest hours of the day (between 2 and 3 PM); this can help prevent sunburn and leaf scorch. Styrax trees require well-draining, moist soil that is slightly acidic. They prefer a soil pH of between 5.5 and 6.5, but can tolerate neutral soils as well if necessary. They do not like having standing water around their roots, so avoid planting them in a depressed area of the landscape. Ensure that soil has good drainage before planting; otherwise amend with plenty of sand and organic matter before installation. Post-planting, apply a layer of mulch around the base of the tree. Doing so will increase soil moisture retention, suppress weed growth, and regulate soil temperatures. During the first few years, water trees regularly to help them establish a good root system. At maturity, Styrax appreciate consistent soil moisture; as a general rule of thumb, water whenever the top inch or two of soil feels dry to the touch.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Minimal pruning is needed for Styrax trees; they typically have a natural graceful form. In early spring, simply remove dead, damaged, diseased, or crossing branches. Trees should be shaped when they are young, not after they have matured. As they grow, make sure to lightly thin out the canopy every few years to increase air circulation. These are long-lived perennial trees, able to survive for 50 to 100 years or more before needing to be replaced. They grow at a slow rate, reaching their mature size in 15 to 20 years.

Propagation

Styrax can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Styrax, follow the instructions below:

Propagating Styrax 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. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
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 softwood 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.

Propagating Styrax by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a resealable plastic bag, peat moss, pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods on Styrax plants are pretty easy to spot, they're large and dangle from the branches, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Styrax seeds need to undergo a few treatments before they will readily germinate. Place your seeds in a resealable plastic bag filled with moistened peat moss, and put it in an area that stays at about 65 degrees Fahrenheit, and leave it there for 4 weeks. Ensure that the bag stays moist during these treatments by adding sprays of water as necessary. Once the four weeks has passed, move the bag to your refrigerator and leave it for 11 weeks. When both of these treatments are done, remove your seeds from the bag.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 14-21 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. 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 (after the danger of frost has passed), when you can transplant it to its new home.