Alder Buckthorn
Rhamnus alnifolia
Rhamnaceae · broadleaf deciduous shrub · introduced
Last updated
Quick Facts
Height
3 ft
Growth Rate
Moderate
Light
Part Shade
Soil
Wet Tolerant
Water
High
Hardiness
Zone Zones 4a–9b
Bloom Time
May 1-May 31
Watch for this season
Nectria CankerHigh
Spore Release (Fall & Spring Rains)
RustHigh
Aecial Stage (Alternate Host)
Tent caterpillarHigh
Larval Feeding
Armillaria Root RotModerate
Active Below-ground Growth
+ 3 more — see full disease and pest lists below
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 |
| Leaf drop BBCH 93 | Oct 15-Nov 30 |
| Dormancy BBCH 97 | Nov 15-Feb 28 |
Diseases: Regionally Documented (11)
Armillaria spp. — primarily A Armillaria Root Rot Brown Leaf Blotch [VERIFY] Canker and Stem Diseases Viral agents Catkin Hypertrophy and Leaf Curl Collar Rot Lonsdalea quercina subsp Drippy Dieback Symptom category — not a single disease Leaf Spot Neonectria ditissima Nectria Canker Phytophthora spp. (P Phytophthora Root Rot Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew Multiple genera (Melampsoridium, Thekopsora, Naohidemyces... Rust
Pests: Regionally Documented (4)
Data Maturity Structured Multiple sources. Expert review underway.