High Maintenance and Problem Plants
in the Pacific Northwest
Alder----Caterpillars, brittle branches, surface roots
Alpine firs----Balsam woolly adelgid, Aphids, Mites, Rust
Bamboo----Invasive roots (non-invasive varieties: Sinarundinaria muriele, Shibataea kumasasa)
Birch----Aphids, Borers, Caterpillars, Leafminer, surface roots, twig drop
Broom----Short lived, allergenic
Ceanothus----Root rot, winter damage
Corkscrew willow Aphids, blights
Crabapple----Scab, Cedar Apple Rust.
Resistant varieties: 'Christmas Holly', 'Dolgo', 'Donald Wyman', 'Evereste', 'Indian Magic', 'Indian Summer', 'Malus tschonoski', 'Malus zumi x calocarpa', 'Mary Potter', 'Molten Lava', 'Ormiston Roy', 'Prairifire', 'Professor Sprenger', 'Sugar Tyme', 'Upright David', 'White Angel'
Cherries---- Bacterial and fungus diseases, caterpillars, Scale, surface roots, suckering roots'.
Resistant varieties: Prunus serrulata 'Kwanzan', Prunus 'Okame'
Daphne----Aphids, winter damage. Resistant variety: Daphne burkwoodii
Deodar cedar----Excessive growth, damaged by weedkillers.
Dogwood----Anthracnose. Resistant variety: Cornus kousa
English laurel----Excessive growth, invasive roots
Escallonia----Winter damage
Fruit trees----Aphids, Scale, fungus on leaves and fruit, blights, apple maggot, leaf and fruit insects
Hawthorn---- Aphids, leaf insects, Scale, fungus leaf spot. Resistant variety: Crataegus x lavallei
Honey Locust----Leaf Gall, invasive and suckering roots.
Juniper----Branch dieback, blights, Scale, root rot.
Lilac----Leaf miner, blight, Powdery Mildew.
Madrona----Leaf spot
Magnolia grandiflora----Excessive growth, snow damage
Maples----Aphids, Scale, fungus on leaf and branches
Mexican orange----Winter damage
Oriental Thuja---- Blight, snow damage
Photinia---- Excessive growth, leaf spot, winter damage
Poplar----Invasive roots, brittle branches
Port Orford Cedar---- Root rot
Privet----Invasive roots, winter damage
Pyracantha----Scab, winter damage, excessive growth
Raphiolepis----Winter damage
Rose----Aphids, blights, Canker, Crowngall, Rust, Mildew, viruses
Resistant varieties: Shrub and Rugosa roses
Silk tree----Canker, root rot
Skimmia----Mites
Spruce----Aphids, Spider Mites, Galls
Resistant variety: Picea omorika
Sumac----Suckering roots
Willow----Invasive roots, brittle branches
This material is the copyright of Patricia M. Roome and PAT ROOME Landscape Design Inc.
Permission to use this material is hereby granted, providing full recognition of copyright and authorship is acknowledged.
For more information contact your local WSU Extension Office.
