Common Cultural: Air pollution categories: Common Problems Cultural Problems last review date: 2025-08-15 11:34 Air pollution damage on dahlia Photo by: R.S. Byther Biology Generally, air pollution damage in the Pacific Northwest has been considered limited. Sulfur dioxide damage from large industrial emissions has been known to cause interveinal bleaching on dahlia, interveinal spotting on […]
Common Cultural: Chlorosis categories: Common Problems Cultural Problems last review date: 2026-03-25 11:57 Chlorosis on Japanese spurge caused by excessive sunlight Photo by: R. Maleike Biology Chlorosis is the fading of the green color in plant leaves. It can be caused by environmental stress, nutrient deficiency, chemical deficiency or injury, disease, and the feeding of […]
Common Cultural: Construction damage categories: Common Problems Cultural Problems last review date: 2026-03-26 12:58 Tree root damage and dieback from construction Photo by: R.S. Byther Biology Disturbances in the root zone such as cutting roots, covering roots with sidewalks or pavement, adding a layer of topsoil, changing soil grade, or changing water drainage patterns can […]
Common Cultural: Desiccating wind categories: Common Problems Cultural Problems last review date: 2026-03-26 01:08 Winter desiccation on rhododendron leaves Photo by: R. Maleike Biology Dry, cold wind, usually from the north, results in desiccation (dehydration) of plant tissues. During periods when the soil is frozen, water movement slows or stops in plant tissue, enabling wind […]
Common Cultural: Drought damage categories: Common Problems Cultural Problems last review date: 2026-03-26 01:26 Dead upper branches on conifer from drought damage Photo by: R.S. Byther Biology Marginal and tip leaf necrosis may result when insufficient moisture is available to broadleaf plants. The terminals growth and sometimes side branches on conifers may die because of […]
Common Cultural: Fasciation categories: Common Problems Cultural Problems last review date: 2026-03-26 01:44 Fasciation showing a flattened, twisted, ribbed stem Photo by: R.S. Byther Biology Fasciation occurs in many kinds of plants, both woody and nonwoody. Stem growth becomes flattened and often takes on a dramatic twisting due to changes in the genetics of the […]
Common Cultural: Fertilizer burn categories: Common Problems Cultural Problems last review date: 2026-03-26 02:12 Marginal leaf necrosis Photo by: R.S. Byther Biology Excessive use of fertilizers can damage or kill plants. High levels of salts in the soil will damage plant roots, resulting in reduced water uptake. The salts may also accumulate in leaf tissues, […]
Common Cultural: Frost injury categories: Common Problems Cultural Problems last review date: 2026-03-26 02:25 Flower bud damage on rhododendron Photo by: R.S. Byther Biology Frost can damage new growth and flowers in the spring. Severity and distribution will depend on stage of plant development and where plants are growing; low-lying areas often act as frost […]
Common Cultural: Hail damage categories: Common Problems Cultural Problems last review date: 2026-03-26 02:48 Tattered leaves and pear fruit damaged by severe hailstorm Photo by: M. Bush Biology Hail damage can vary from minor leaf spots and shredding to complete defoliation. Scarring of fruit may also occur. Minor damage may not be immediately apparent. Distribution […]
Common Cultural: Lime-induced chlorosis categories: Common Problems Cultural Problems last review date: 2026-03-26 02:56 Lime-induced chlorosis on rhododendron Photo by: R.S. Byther Biology Lime-induced chlorosis is a yellowing of leaves caused by alkaline soil conditions. High alkalinity (high pH) of soils can make iron or manganese less available to plants, resulting in symptoms of nutrient […]