Hosts and Pests of Landscape Plants

Michael R. Bush and Sharon J. Collman
March 2021

Includes management options for commercial and home use.

In all cases, follow the instructions on the pesticide label. The PNW Insect Management Handbook has no legal status, whereas the pesticide label is a legal document. Read the product label before making any pesticide applications.

Note: Products are listed in alphabetical order and not in order of preference or superiority of pest control.

We welcome any suggestions for hosts or pests that have not been included in this edition. This is a work in progress and new hosts and pests are added each year. If you are aware of pesticides that have proven to be effective or not, let us know so they can be considered or removed. —Sharon J. Collman (

Alder (Alnus)

Andromeda (Pieris japonica)

Apricot, flowering (Prunus)

Arborvitae (Thuja)

Ash (Fraxinus)

Aspen (Populus tremuloides)

Aucuba (Aucuba japonica)

Azalea (Rhododendron)

Bamboo (Bambusa and others)

Barberry (Berberis)

Beech (Fagus)

Bergenia (Bergenia)

Birch (Betula)

Black locust (Robinia)

Black walnut (Juglans)

Boxelder (Acer negundo)

Boxwood (Buxus)

Butterfly bush (Buddleja)

California lilac (Ceanothus)

Camellia (Camellia)

Cherry, flowering (Prunus)

Chestnut (Castanea)

Cotoneaster (Cotoneaster)

Cottonwood (Populus)

Crabapple, flowering (Malus)

Daffodil (Narcissus)

Dahlia (Dahlia)

Daphne (Daphne)

Dogwood (Cornus)

Douglas-fir (Pseudotsuga)

Elderberry (Sambucus)

Elm (Ulmus)

Euonymus (Euonymus)

Euphorbia (Euphorbia)

Fir (Abies)

Firethorn (Pyracantha)

Forsythia (Forsythia)

Fuchsia (Fuchsia)

Geranium (Pelargonium)

Gladiolus (Gladiolus)

Golden chain (Laburnum)

Hawthorn (Crataegus)

Hellebore (Helleborus)

Hemlock (Tsuga)

Holly (Ilex)

Hollyhock (Alcea rosea)

Honeylocust (Gleditsia triacanthos)

Honeysuckle (Lonicera)

Hydrangea (Hydrangea)

Iris (Iris)

Ivy (Hedera)

Japanese holly (Ilex)

Juniper (Juniperus)

Kinnikinnick (Arctostaphylos)

Kinnikinnik (Arctostaphylos)

Laurel, Portuguese (Prunus)

Lilac (Syringa)

Lily (Lilium)

Linden (Tilia)

Locust (Robinia)

Madrone (Arbutus)

Maple (Acer)

Mountain ash (Sorbus)

Narcissus (Narcissus)

Oak (Quercus)

Peach, flowering (Prunus)

Pear, flowering (Pyrus)

Photinia (Photinia)

Pine (Pinus)

Plum, flowering (Prunus)

Poplar (Populus)

Privet (Ligustrum)

Quince, flowering (Cydonia)

Rhododendron (Rhododendron)

Rockrose (Cistus)

Rose (Rosa)

Sequoia/Redwood (Sequoia)

Skimmia (Skimmia)

Spiraea (Spiraea)

Spruce (Picea)

Sycamore (Platanus)

Tulip (Tulipa)

Tuliptree (Liriodendron)

Viburnum (Viburnum)

Willow (Salix)

Witch-hazel (Hamamelis)

Yew (Taxus)