Japanese pagoda tree

Sun

Full sun; tolerates light shade but flowers less freely.

Water

Water regularly while establishing; established trees tolerate dry spells but benefit from deep watering during prolonged drought.

Soil

Well-drained soil, including clay, loam and sandy soil; tolerates alkaline conditions and moderately poor soil, but not persistent waterlogging.

Height

50-75 ft (15-23 m)

Spread

40-60 ft (12-18 m)

Flowers

Late summer to early autumn; branched, hanging clusters of small creamy-white, pea-shaped flowers. Flowering can be sparse in cool-summer areas.

Foliage

Pinnate leaves with oval, dark green leaflets; autumn colour is usually yellow-green to yellow and can be brief.

Growth

Moderate, sometimes faster when young on good soil.

Care needed

Medium

• Pollinators
• Drought tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   7 ft (2.3 m)

2. After 1 year

   11 ft (3.3 m)

3. After 2 years

   14 ft (4.4 m)

4. After 3 years

   18 ft (5.4 m)

5. After 5 years

   25 ft (7.5 m)

About 16 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Fast

• Plant where the mature crown has room to spread, away from buildings and overhead wires.
• Water deeply through the first two growing seasons, allowing the soil surface to dry between waterings.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the trunk.
• Avoid routine high-nitrogen feeding; feed only if poor growth or a soil test indicates a need.
• Stake only if the root ball moves in wind, and remove ties once the tree is securely rooted.
• Keep fallen flowers and pods cleared from paths, where they can make a slippery mess.

Pruning. In late winter, train young trees to a sound framework with well-spaced branches and remove competing leaders or narrow, weak forks. Once established, remove only dead, damaged or crossing branches; use a qualified arborist for large limbs.

Autumn

Plant while the soil is workable in mild climates; in cold regions, wait until spring.

Late winter

Check branch structure and carry out light formative pruning before new growth begins.

Spring

Plant in colder regions, refresh mulch and check that stakes and ties are not rubbing.

Summer

Deep-water young trees during dry weather and inspect leaves and shoots for pests.

Late summer

Enjoy the flowers and sweep fallen blooms from paving.

Late autumn

Clear fallen pods from paths and areas used by children or animals.

• Use as a specimen in a large lawn, allowing its broad crown to develop without crowding.
• Plant for summer shade beside a spacious seating area, allowing for flower and pod litter.
• Combine with ornamental grasses and sun-loving perennials around the outer edge of the canopy.
• Use in large urban gardens or park-like settings where heat, alkaline soil and occasional drought limit less adaptable trees.

Garden styles it suits: Grand estate, Urban city garden, Traditional, Chinese scholar garden, Japanese and Pollinator garden.

Plant it with: Catmint, Russian sage, Switchgrass, Purple coneflower, Hardy geranium and Lilyturf.

Wildlife: Flowers provide late-season nectar and pollen for bees and other insects. The mature crown offers shelter and nesting sites for birds.

• Weak forks and branch breakage: train young trees early and have large or defective limbs assessed by an arborist.
• Cankers and twig dieback: prune affected growth back to healthy wood in dry weather, avoid trunk injuries and reduce drought stress.
• Aphids or scale insects: inspect shoots and leaf undersides; tolerate light infestations and use a labelled horticultural oil when treatment is necessary.
• Little or no flowering: young trees and trees in cool summers may flower poorly; provide full sun and avoid heavy nitrogen feeding.

Seeds and pods are reported poisonous if eaten and should not be treated as edible. Keep them away from children, cats, dogs and horses; species-specific information on toxic doses is limited, so seek medical or veterinary advice after ingestion rather than assuming it is harmless.

• Black locust (Robinia pseudoacacia)

  Black locust usually has paired thorns on young shoots, flowers in spring and produces flat pods. Japanese pagoda tree is thornless, flowers in late summer and has pods constricted between the seeds.

• Honey locust (Gleditsia triacanthos)

  Honey locust has smaller leaflets, sometimes twice-divided leaves, inconspicuous flowers and long, flat, often twisted pods; the species also bears large branched thorns.

• Japanese wisteria (Wisteria floribunda)

  Wisteria is a twining climber with long spring flower clusters and velvety pods, rather than a self-supporting tree with late-summer flowers and bead-like pods.

The name japonicum refers to Japan, where the tree has long been cultivated despite its Chinese and Korean origins, while 'pagoda tree' reflects its traditional planting near temples.

Propagation. Grow the species from seed after carefully nicking the hard seed coat and soaking the seed before sowing. Seedlings vary and can take many years to flower; named cultivars are usually grafted.

Accepted botanical name

Styphnolobium japonicum

In the US and Canada

Introduced in the lower 48 states.

Native range

China North-Central, China South-Central and China Southeast.

Measured

Soil pH 6.5 to 7. Average height 1800 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.