Mallow Ninebark
Physocarpus malvaceus
Rosaceae · broadleaf deciduous shrub · introduced
Last updated
Physocarpus malvaceus (Rosaceae) is a deciduous shrub native to the interior mountains of western North America. It grows 3 to 6 feet tall with arching stems and exfoliating bark. White to pinkish flower clusters appear in late spring. The maple-like leaves distinguish it from the closely related P. capitatus.
Mallow ninebark is adapted to drier sites than P. capitatus and tolerates well-drained, rocky soils in full sun to light shade. It is common in open forests and on exposed slopes. No significant pest or disease problems are documented. Hardy in Zones 4a to 8b.
Plant Profile
Size & Form
Height
2–7 ft
Growth Rate
Fast
Size at 20 yr
15 ft
Lifespan
Long-lived
Site Requirements
Light
Full Sun
Soil Drainage
Wet Tolerant
Soil pH
6.0-7.5
Water
Low
Drought Tolerance
High
Hardiness
Zones 5a–8b
Ornamental Interest
Bloom Time
late spring
Origin
Pacific Northwest native
Watch for this season
Powdery MildewHigh
Active Conidial Spread
Diseases: Regionally Documented (1)
Phenological Calendar
View full calendar (8 stages)
| Stage | Typical Window |
|---|---|
| Bud break BBCH 07 | Feb 15-Mar 15 |
| Leaf emergence BBCH 11 | Mar 1-Apr 1 |
| Bloom start BBCH 61 | May 1-May 31 |
| Bloom end / petal fall BBCH 69 | May 15-Jun 15 |
| Fruit/seed development BBCH 71 | Jun 1-Aug 31 |
| Fruit/seed maturity BBCH 85 | Sep 1-Nov 30 |
| Fall color / leaf senescence BBCH 93 | Oct 1-Nov 15 |
| Dormancy BBCH 97 | Nov 15-Feb 28 |
Data Maturity Baseline Extension data. Expert review underway.