What actually goes wrong with Colorado shrubs.

Alberta spruce is a slow-growing, dense, evergreen conifer commonly used as an accent plant, entryway anchor, or formal foundation shrub. In Colorado, most decline problems are tied to dry winter wind/sun, drought stress, and mite pressure, especially when plants are in hot exposures or allowed to dry out.

Arborvitae are popular evergreen screens in Colorado but are highly sensitive to drought, winter burn, hot sun exposure, and spider mites. Most issues trace back to water stress, root problems, or environmental extremes, rather than insects.

Arctic willow problems in Colorado landscapes: identify aphids, willow leaf beetle, scale, canker and leaf spot, and see when to treat dwarf willows on the Front Range.

Barberry is a dense, thorny shrub commonly used for hedges, barriers, and foundation plantings. In Colorado it’s generally tough, but can still be affected by sap- feeding insects, mites, and a few foliar diseases—especially when crowded or stressed.

Boxwood is a popular evergreen shrub commonly used for hedges and foundation plantings. In Colorado, it is affected by winter desiccation, leafminer, psylla, mites, and several fungal issues. Most problems are manageable with proper watering and pruning.

Burning bush is a dense, deciduous shrub valued for bright fall color and hedge screening. In Colorado it’s generally tough, but drought stress and dense growth can allow mites, scale insects, and foliar diseases to develop.

Common lilac problems in Colorado: identify lilac leafminer, powdery mildew, bacterial blight, borers and scale, with symptoms, seasonal timing and homeowner treatment options.

Currants are deciduous shrubs grown for fruit, pollinators, and hardy landscape use. In the Colorado Front Range, most issues are seasonal and tied to sap- feeding insects, defoliators, foliar diseases, and stress. Good airflow, consistent watering, and annual cane renewal solve most problems.

Hydrangea is a showy, deciduous flowering shrub prized for large blooms and lush foliage. In Colorado, hydrangeas do best with morning sun / afternoon shade, consistent moisture, and mulch to keep roots cool. Most problems show up when plants are drought-stressed, heat-stressed, overcrowded (poor airflow), or watered overhead.

Ninebark (Physocarpus opulifolius) problems in Colorado: identify powdery mildew, spider mites, scale, aphids and canker, with a seasonal calendar and practical treatment guidance.

Potentilla is a hardy, deciduous flowering shrub widely used in Colorado landscapes for its long bloom season and toughness. It prefers full sun and well-drained soil; most issues show up when plants are crowded, stressed, or kept too wet.

Privet is a dense, fast-growing shrub commonly used for hedges, screens, and foundation plantings. In Colorado it is generally tough, but drought stress, dense growth, and poor airflow can allow sap-feeding insects, mites, and foliar diseases to develop—especially on tightly clipped hedges. Shrub / hedge habit Flowers (late spring–summer)

Roses are classic flowering shrubs valued for color, fragrance, and long bloom season. In Colorado, most problems show up when roses are drought-stressed, heat-stressed, crowded (poor airflow), or watered overhead. Consistent deep watering, mulch, and good pruning practices prevent most issues.

Spirea is a compact, deciduous flowering shrub commonly used in foundation plantings and mass beds. In Colorado it is generally low-maintenance, but drought stress, dense growth, and poor airflow can allow insects and foliar diseases to develop.

Viburnum is a popular deciduous (some semi-evergreen) flowering shrub used for hedges, screens, and foundation plantings. Many viburnums provide spring flowers, fall color, and berries. In Colorado, most issues are seasonal and manageable with proper watering, pruning, sanitation, and timely scouting.

Yews are durable, shade-tolerant evergreens widely used in Colorado landscapes. They are generally tough but can suffer from winter burn, root issues, needle blight, and occasional insect pests. Yews are highly sensitive to overwatering and poor drainage, which is the #1 cause of decline in Colorado soils.

4 tracked problems · full health profile

Powdery mildew in shaded or crowded sites (mid summer–fall).

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Leaf scorch during extreme heat or drought.

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Winter burn in exposed locations.

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Root rot in overwatered or poorly drained beds.

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Scale insects on stressed or crowded plants.

3 tracked problems

Winter dieback on tips in severe seasons.

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Winter burn and bronzing on exposed foliage.

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Winter tip dieback in severe seasons.

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Powdery mildew in crowded or shaded plantings.

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Powdery mildew in low-airflow sites.

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Woody, open centers when never pruned.

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Powdery mildew in crowded plantings.

3 tracked problems

Euonymus scale — the most common and most damaging pest of this species.

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Iron chlorosis in alkaline soils.