Pest Tolerance of Ornamental Plants

Copyright 1995 IPMPA

One of the keys to designing a low-maintenance landscape that requires minimal use of pesticides is choosing plants that are naturally resistant to pest problems(including diseases). A particular plant's resistance or susceptibility to pests is variable and depends on individual plant characteristics (e.g., a rolled leaf margin versus a flat leaf margin); the type, proximity, and abundance of local pest populations; and the health of the plant. It is well documented that pests seek unhealthy plants to feed upon, that healthy plants are much more capable of rebounding after a pest infestation, and that healthy plants can actually prevent pests from reaching damaging population levels.

Unfortunately, while there is an abundance of information concerning which pests are common to particular plants and how these pests can be chemically controlled, there is little information indicating which plants have significant (i.e., meaningful) pest problems. Several publications that provide useful, although limited, information on insect pests and diseases of ornamental plants are listed below. Local landscape professionals, nurseries, and garden centers, whose knowledge is a result of years of experience from working with and observing ornamental plants can also provide valuable information for selecting pest resistant plants.

Another valuable source of information concerning the resistance and susceptibility of various plants to specific pests are historical pest management records and observations. For example, during an IPM pilot project for Seattle City Light utility in Seattle, Washington, landscape maintenance employees used their experience to identify pests that traditionally cause unacceptable losses on the utility's landscapes. Of the numerous pests/diseases that occur in the Pacific Northwest, only a handful were considered a problem. Of these, only three insect pests were of major importance - root weevils, aphids, and scales. As a result of this exercise, it became clear that it would be fruitful for City Light to minimize the use of plants that are prone to damage from these insects. Likewise, an IPM program developed by the University of Maryland's Extension Service identified the most commonly used plants and those which had the fewest, as well as those which had the most, pest problems. These can be useful models for developing similar lists for plants on other landscapes.


Resources for Further Information Regarding Diseases and Insect Pests of Ornamental Plants

Brown, George E. 1972. The Pruning of Trees, Shrubs, and Conifers. Faber and Faber, London. 351 pp.

Cook, Thomas. 1989. Landscape Maintenance - Oregon State University Hort. 315 Class Packet (Reprints). 218 pp.

Davidson, Ralph H. and Lyon, William F. 1987. Insect Pests of Farm, Garden, and Orchard, 8th Ed. Wiley, N. Y. 640 pp.

DeAngeles, Jack, et al. 1989. Pacific Northwest Insect Control Handbook. Extension Services of Oregon State Univ., Washington State Univ., and the Univ. of Idaho. 338 pp.

Dirr, Michael A. 1983. Manual of Woody Landscape Plants, 3rd Ed. Stipes, Champaign, IL. 826 pp.

Flint, M. L. 1990. Pests of the Garden and Small Farm. University of California, Division of Agriculture and Natural Resources, Oakland, California. 276 pp.

Gilberg, L., ed. 1993. Garden Pests and Diseases. Sunset, Menlo Park, California. 112 pp.

Gerber, H. S., N. V. Tonks, and D. A. Ross. 1992. Insect and Mite Pests of Ornamental Shrubs and Shade Trees of British Columbia. Province of British Columbia, Ministry of Agriculture and Food, Victoria, British Columbia Canada. 53 pp.

Harris, Richard W. 1983. Arboriculture: Care of Trees, Shrubs, and Vines in the Landscape. Prentice-Hall, Englewood Cliffs, NJ. 688 pp.

Johnson, Warren T. and Lyon, Howard H. 1988. Insects that Feed on Trees and Shrubs, 2nd Ed. Cornell Univ. Press, Ithaca, NY. 556 pp.

Koehler, C. S. 1987. Insect Pest Management Guidelines for California Landscape Ornamentals. University of California, Division of Agriculture and Natural Resources. 82 pp.

MacSwan, Iain C., et al. 1983. Pacific Northwest Plant Disease Control Handbook. Extension Services of Oregon State Univ., Washington State Univ., and the Univ. of Idaho. 257 pp.

Olkowski, W., S. Daar, and H. Olkowski. 1991. Common-Sense Pest Control. Taunton, Newtown, Connecticut. 715 pp.

Orton, Donald A. 1989. Coincide - The Orton Method of Pest Management (Timing Pest Management with Ornamental Plant Development). Plantsmen's, Flossmoor, IL. 190 pp.

Pirone, Pascal P. 1978. Diseases and Pests of Ornamental Plants, 5th Ed. Wiley, New York, NY. 566 pp.

Ware, George W. 1980. Complete Guide to Pest Control - With and Without Chemicals. Thomas, Fresno, CA. 290 pp.

Wiese, Suzanne and Nancy Hansen. 1992. The IPM Alternative: Least Toxic Techniques for Lawn and Garden Care. City of Bellevue Storm and Surface Water Utility, Bellevue, Washington.

Williamson, Joseph F., et al. 1988. Sunset Western Garden Book. Lane, Menlo Park, CA. 592 pp.

Wirth, Thomas. 1985. The Victory Garden Landscape Guide. Little, Brown, Boston. 360 pp.

Yepson, Jr., Roger B., Ed. 1984. The Encyclopedia of Natural Insect and Disease Control. Rodale, Emmaus, PA. 490 pp.


Last Modified: Tuesday, August 15, 1995 - 3:25:18 PM

Source: IPM Access - An Integrated Pest Management Online Service

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