The Japanese snowbell tree (Styrax japonicus) is a small, deciduous tree native to Japan, Korea and China. It is known for its graceful shape, fragrant spring flowers and vibrant fall foliage. If you are considering adding a Japanese snowbell to your landscape, you likely want to know how fast it will grow to reach its mature size.
Typical Growth Rate
In general, Japanese snowbell trees are relatively slow growing. They tend to grow at a rate of anywhere from less than 12 inches to 24 inches per year when they are young. As they mature, their growth rate slows down even more. You can expect an established snowbell tree to put on around 6 to 12 inches of growth annually once it reaches maturity.
Seedling vs Grafted
Whether you start with a seedling tree or a grafted variety can impact its initial growth rate. Seedling snowbell trees tend to be slower growing when initially planted. Grafted snowbells have the advantage of being propagated from cuttings of mature trees, so they tend to grow a bit faster out of the gate.
Tree Size at Planting
The size of the Japanese snowbell when you first plant it also affects how quickly it grows. Smaller, younger trees less than 5 feet tall may grow up to 2 feet per year. More mature snowbell trees over 8 feet tall are slower growing and may only add 6-12 inches of growth annually.
Soil, Sun and Climate
Like any plant, the growing conditions for the snowbell tree impact its growth rate. Some factors that support faster growth include:
- Planting in moist, well-draining, fertile soil.
- Full sun to partial shade exposure.
- Adequate summer rainfall and humidity.
- Protection from strong winds.
Trees planted in poor, dry soils or extreme climates will grow slower.
Pruning and Care
Providing proper care by watering, fertilizing, pruning and protecting your Japanese snowbell helps keep it healthy and supports a faster growth rate. Make sure it gets regular irrigation and prune only as needed to maintain its natural form. Fertilize lightly in early spring.
Typical Height Growth by Age
Based on average growth rates, you can expect a newly planted snowbell tree to reach the following heights as it matures:
| Tree Age | Expected Height |
|---|---|
| 3 years | 4 – 8 feet |
| 5 years | 8 – 12 feet |
| 10 years | 15 – 20 feet |
| 15 – 20 years | 20 – 30 feet |
These growth rates assume the tree is planted in an ideal growing site and given proper care. Growth may be slower in poor conditions.
Maximum Mature Height and Spread
Given the right growing conditions, a Japanese snowbell tree can reach a typical mature size of 20 to 30 feet tall and 15 to 25 feet wide. Some varieties may reach 35 to 45 feet tall at maturity. The crown shape is rounded and spreading.
Growth Habit
Japanese snowbell trees have an upright oval to rounded growth habit when young. As they mature and produce flowers, the weight of the blooms causes the branches to become more spreading and vase-shaped. Some pendulous branching also occurs.
Flowers
One of the most prized features of the snowbell tree is its spring flowers. The blossoms emerge as early as March and April, depending on your climate. They are delicate, white and bell-shaped, blooming in clusters along the branches. Flowering contributes to the spreading growth habit in mature trees.
Foliage
The leaves of the Japanese snowbell tree emerge in a reddish-purple color and mature to a lush green. In fall, the foliage transforms again to shades of yellow, orange and red before dropping. The leaves are oval to elliptic in shape and arranged alternately along the stems. They can reach 2 to 5 inches long.
Factors That Stunt Growth
While Japanese snowbell trees tend to grow at a moderate pace, there are some factors that can stunt their growth:
- Insufficient water – Drought stunts growth.
- Poor soil – Sandy, heavy clay or rocky soil inhibits growth.
- Poor drainage – Standing water causes root rot.
- Lack of sun – At least 6 hours of sun is required.
- Severe pruning – Removing too much growth delays growth.
- Damage – Deer, insects, diseases, weather damage reduce growth.
Addressing these issues can help get your snowbell tree growing faster again.
Pruning to Stimulate Growth
Occasional corrective pruning to remove dead or damaged branches can encourage new growth. Avoid overpruning, as too much cutting back slows growth. Light thinning to allow air circulation also stimulates bud growth. Focus pruning efforts in late winter when the tree is dormant.
Fertilizing for Growth
Use a balanced, slow-release fertilizer every 2-3 years in early spring to provide nutrients that fuel new growth. Compost also enriches the soil. Avoid over-fertilizing, as excess nutrients can damage the tree.
Watering for Healthy Growth
Ensure your Japanese snowbell receives consistent moisture, especially while young. Water deeply once a week during dry periods for strong growth. Established trees are moderately drought tolerant but benefit from regular watering.
Protecting Tree Health
Preventing disease, insects and animal damage keeps your snowbell tree healthy so it can reach its full potential. Watch for issues like powdery mildew, scale insects and deer browsing. Take action promptly if problems occur.
Choosing a Fast-Growing Variety
Some named varieties of Japanese snowbell trees are known for their vigorous growth habits, including:
- Pink Chimes – Grows up to 3 feet per year when young.
- Summer Snowflake – Moderate growth to 30 feet.
- Carillon – Very showy flowers support faster growth.
- Rosea – Pink blooms, grows quickly.
Consult with your local nursery to select a fast-growing snowbell cultivar suited to your climate.
Transplanting Established Trees
Moving a Japanese snowbell from one spot to another in the landscape shocks the tree and slows growth temporarily. Reduce this impact by transplanting in early spring, digging up the entire root ball, and providing ample water and mulch after replanting. It may take a year or two for the tree to recover fully and resume faster growth.
Is Fertilizer Necessary?
Fertilizer is usually not required for Japanese snowbell trees to achieve moderate growth rates. However, applying a balanced, extended-release fertilizer every 2-3 years in early spring can provide a boost of nutrients that fuels faster growth for that season.
Use about 1/2 to 1 pound of fertilizer per inch of trunk diameter, spread around the base under the tree’s drip line. Water in well after application. Avoid fertilizing in fall to prevent winter damage or late season growth.
Growth Rate Comparison
The Japanese snowbell is relatively slow growing compared to other landscape trees. Here is how its growth rate compares:
| Tree | Growth Rate |
|---|---|
| Japanese snowbell | 12-24 inches per year when young |
| Red maple | 24-36 inches per year when young |
| River birch | Up to 5 feet per year when young |
| Eastern redbud | 12-24 inches per year |
While not the fastest growing, the snowbell tree’s moderate growth habit makes it suitable for many landscapes.
Tips for Faster Growth
Follow these tips to help your Japanese snowbell tree grow faster:
- Plant in spring.
- Choose a fast-growing cultivar.
- Plant in full sun to partial shade.
- Provide well-drained, fertile soil.
- Water thoroughly when young.
- Mulch around the base.
- Fertilize lightly every few years.
- Prune only as needed.
Troubleshooting Slow Growth
If your Japanese snowbell tree is growing slower than expected, check for these common issues:
- Underwatering – Regular irrigation is key for growth.
- Insufficient light – Move to a sunnier spot.
- Compacted soil – Aerate and amend the soil.
- Damage – Check for disease, pests, injury.
- Poor drainage – Improve drainage in soggy areas.
- Root competition – Remove surrounding sod or weeds.
- Harsh pruning – Avoid overpruning and shape lightly.
Correcting any care issues will help get your tree growing faster again.
When to Expect Faster Growth
The Japanese snowbell experiences flushes of fast growth at certain times:
- Spring – New shoot growth emerges when dormancy breaks.
- Summer – Warm temperatures and rainfall support growth.
- Early years – Young trees under 5 feet tall grow rapidly.
Expect to see the most dramatic growth during the first 5 years. Monitor soil moisture and fertilize in spring to fuel growth all season.
Conclusion
The Japanese snowbell tree grows at a moderate pace, averaging 1 to 2 feet of new growth per year when young. Mature height typically reaches 20 to 30 feet tall and wide. Providing ideal growing conditions including sun, moisture and well-drained soil will maximize growth rate. With proper care, this graceful flowering tree can make a stunning addition to gardens and should grow fast enough to start enjoying in just a few seasons.
