Mallow Ninebark
Physocarpus malvaceus
Rosaceae · broadleaf · native
Mallow ninebark appears in dry, open sites throughout the interior Pacific Northwest from the east Cascades to the Rockies, from British Columbia to California. You will notice the plant's signature exfoliating bark, which peels away in long, papery irregular strips from stems to create a mottled tan and brown appearance.
Mallow ninebark is extraordinarily drought and heat tolerant once established, thriving on sandy, gravelly, or volcanic soils with minimal water (8-24 inches annual precipitation across its range). Plant in full sun and provide good drainage; overwatering and shade promote weakness.
Quick Facts
Height
2–7 ft
Growth Rate
Fast
Light
Full Sun
Soil
Wet Tolerant
Water
Low
Hardiness
Zone Zones 5a–8b
Bloom Time
May 1-May 31
Origin
Pacific Northwest native
Phenological Calendar
| 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 |