California Sycamore

Platanus racemosa

Platanaceae · broadleaf deciduous tree · introduced

Last updated May 27, 2026

Plant Profile

Size & Form

Height

40–80 ft

Spread

20-50 ft

Growth Rate

Slow

Size at 20 yr

20 ft

Lifespan

Long-lived

Site Requirements

Light

Full Sun

Soil Drainage

Wet Tolerant

Soil pH

5.8-7.3

Water

Moderate

Drought Tolerance

Medium

Hardiness

Zones 7a–8b

Ornamental Interest

Bloom Time

mid spring

Fall Color

Yes

Origin

California (foothills and Coast Range) and Baja California

Powdery MildewHigh

Active Conidial Spread

AphidHigh

Peak Population & Dispersal

Fall webwormHigh

Larval Feeding & Web Building

Diseases: Regionally Documented (2)

Apiognomonia veneta (syn. Gnomonia platani) Sycamore Anthracnose Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew

Pests: Regionally Documented (3)

Aphidoidea Aphid Hyphantria cunea Fall webworm Stomacoccus platani Sycamore scale

Phenological Calendar

View full calendar (7 stages)

Stage	Typical Window	What to Look For
Bud break BBCH 07	Feb 15-Mar 15	Buds swelling and beginning to open; first green tissue visible
Leaf emergence BBCH 11	Mar 1-Apr 1	First leaves fully unfurled on new growth
Bloom start BBCH 61	Apr 1-Apr 30	First open flowers visible; flowers yellow
Bloom end / petal fall BBCH 69	Apr 15-May 15	Last petals falling; flower structures fading
Fruit/seed development BBCH 71	Sep 1-Nov 30	Fruit or seed structures forming; fruit color: brown
Leaf drop BBCH 93	Oct 15-Nov 30	Leaves yellowing and dropping; no significant fall color display
Dormancy BBCH 97	Nov 15-Feb 28	Leafless; no active growth; dormant buds set

Data Maturity

Structured Multiple sources. Expert review underway.