How to Manage Pests

Pests in Gardens and Landscapes

Alder—Alnus spp.
Family Betulaceae (Birch family)

Plant Identification

Alders are fast-growing deciduous trees. They vary in size depending on species; most grow between 40 to 60 feet tall. Female flowers develop small cones.

Optimum conditions for growth

The climatic zone for Alnus spp. varies by species. They will grow in shady areas or in full sun and are tolerant of many soils. Alders are moisture loving trees. They do best with deep watering to avoid surface root problems.

Mature white alder, alnus rhombifloia
Mature white alder, Alnus rhombifolia

Pests and disorders of Alnus spp.


Invertebrates (cont.)


Environmental disorders

Parasitic plants



Female cone
Female cone
Male catkin
Male catkin

Statewide IPM Program, Agriculture and Natural Resources, University of California
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