Types of Colorado Trees That Attract Pollinators

Trees are foundational elements in landscapes and ecosystems, and in Colorado they can be powerful magnets for pollinators when chosen and managed correctly. Pollinators include bees, butterflies, moths, hummingbirds, and other insects that move pollen and enable fruit set and plant reproduction. In semi-arid and mountain climates such as Colorado’s, properly selected trees provide nectar, pollen, and larval host resources across a long season, help stabilize soils, shade microhabitats, and increase biodiversity. This article describes tree species and groups that reliably attract pollinators in Colorado, explains how trees function as pollinator habitat, and gives practical, site-specific guidance for planting and maintenance.

Why trees matter for pollinators in Colorado

Trees offer several unique functions for pollinators that small flowering plants cannot replace. They often provide large amounts of nectar and pollen in concentrated periods, they bloom at different times of year than many perennials, and they serve as host plants for butterflies and moths whose caterpillars require woody hosts. In Colorado’s elevation gradient and variable precipitation, trees also create sheltered microclimates where pollinators can forage or nest during hot, cold, or windy periods.
Two important ecological roles to remember:

Many trees are excellent nectar and pollen sources for adult pollinators (foraging resources).
Other trees act as host plants for insect larvae, supporting the full life cycle of butterflies, moths, and some native bees.

Both functions are essential for sustaining robust pollinator populations locally.

How to choose trees for pollinators in Colorado

Selecting the right tree requires attention to elevation, soil, water availability, sun exposure, and desired bloom timing. Colorado spans plains, foothills, montane and subalpine zones; a species that thrives at 5,000 feet on the Front Range may struggle at 9,000 feet in the mountains. Prioritize native species when possible, as native pollinators have co-evolved with local plants. If you choose non-native ornamental trees, favor those known to offer nectar or pollen and avoid sterile cultivars that produce little floral resource.
Practical selection principles:

Provide a succession of bloom times: early-, mid-, and late-season trees to feed pollinators across the growing season.
Choose a mix of species that supply both nectar/pollen and larval-host foliage.
Match water needs to site conditions; drought-stressed trees produce poorer floral resources.
Avoid systemic insecticides and broad-spectrum sprays, especially during bloom.

Native and well-adapted Colorado trees that attract pollinators

Below are trees and tree-like shrubs commonly used in Colorado landscapes that provide meaningful pollinator value. For each species or group I note bloom timing, pollinator beneficiaries, and practical planting notes.

Willows (Salix spp.)

Willows are among the earliest-flowering woody plants in Colorado, often blooming as catkins in late winter to early spring.

Bloom timing: very early spring (catkins).
Pollinators: native bees, early solitary bees, some syrphid flies; willow foliage is also host for many butterfly and moth larvae.
Planting notes: prefer moist soil and riparian zones or irrigated landscapes. Excellent for stabilizing streambanks and supporting early-season pollinators when few other resources exist.

Serviceberry (Amelanchier alnifolia)

Serviceberry (also called Saskatoon) is a multi-stemmed tree or shrub producing white spring blossoms followed by berry crops.

Bloom timing: mid to early spring.
Pollinators: bees and butterflies; fruit attracts birds that help seed distribution.
Planting notes: drought tolerant once established; good choice for foothills and Front Range gardens. Provides nectar and larval host value.

Chokecherry (Prunus virginiana) and Wild Plums (Prunus spp.)

Chokecherry and native plum species have fragrant clusters of white flowers that bees love.

Bloom timing: mid spring.
Pollinators: a wide variety of bees and some butterflies. Fruit is valuable to birds and mammals.
Planting notes: tolerant of a range of soils; useful in windbreaks and wildlife hedgerows. Provide important early-season nectar and later fruit.

Hawthorn (Crataegus spp.)

Hawthorns produce abundant spring flowers and are excellent for bees.

Bloom timing: late spring.
Pollinators: honeybees, native bees, some moths; fruits feed birds.
Planting notes: many hawthorn cultivars tolerate urban conditions and dry soils; be mindful of thorns in planting locations.

Mountain ash / Rowan (Sorbus spp.)

Trees in the Sorbus group produce dense clusters of small white flowers and attractive berry clusters later in the season.

Bloom timing: mid to late spring.
Pollinators: bees and flies for flowers; fruits are important for migrating birds.
Planting notes: hardy in many Colorado zones; select species appropriate to elevation.

Apple and Crabapple (Malus spp.)

Orchard and ornamental apple trees are superb pollinator magnets when in bloom.

Bloom timing: mid spring.
Pollinators: domestic honeybees, native bees, and many flies and beetles; apple blossoms are highly attractive and nectar-rich.
Planting notes: choose disease-resistant cultivars, avoid heavy pruning during bloom, and plan for pollination partners if fruit production is desired.

Linden (Tilia spp.)

Lindens (basswood) bloom later in the season and produce fragrant nectar-rich flowers that bees adore.

Bloom timing: mid to late summer.
Pollinators: honeybees, bumblebees, many native bees, and occasionally butterflies and moths.
Planting notes: lindens can be used in urban streetscapes or parks and provide a valuable late-season nectar source when many wildflowers have finished blooming.

Cottonwoods and Poplars (Populus spp.)

Cottonwoods produce catkins in spring. While many Populus species are wind-pollinated, their early-season pollen and catkins can still provide resources, and their foliage supports a host of caterpillar species.

Bloom timing: early spring.
Pollinators: some bees and early-season insects forage catkins; many butterflies and moths use Populus as host plants.
Planting notes: cottonwoods are large, short-lived, and prefer riparian environments. Plant where root systems and size are appropriate.

Oaks and other host trees (Quercus spp.)

Oaks are primarily wind-pollinated and not major nectar sources, but they are keystone species for insects.

Bloom timing: spring (wind-pollinated flowers).
Pollinators/beneficiaries: support hundreds of caterpillar species, which in turn support birds and predatory insects; essential for lepidopteran life cycles.
Planting notes: plant oaks for biodiversity, habitat complexity, and long-term ecosystem function rather than direct nectar provision.

Practical planting and maintenance recommendations

Successful pollinator trees require planning and ongoing stewardship. The following practical steps will maximize the value of planted trees to pollinators in Colorado.

Select a mix of species with staggered bloom times so forage is available from early spring through late summer.
Prioritize native trees when possible; they are adapted to local climate and matched to native pollinators.
Match tree species to site conditions (elevation, sun exposure, soil moisture). Willows and cottonwoods belong in moist sites; serviceberry and chokecherry perform well in drier foothill sites.
Plant in groups or hedgerows rather than single specimens. Clusters are more easily found by pollinators and provide larger foraging patches.
Provide supplemental water during establishment and drought periods. Healthy trees produce better flowers and pollen.
Avoid using systemic insecticides (neonicotinoids) and broad-spectrum sprays, especially while trees are in bloom. If pest control is necessary, use targeted methods at times when pollinators are not active (late evening) and prefer mechanical or biological controls.
Maintain structural diversity: include shrubs and understory plants that bloom at different times and offer nesting sites for bees.
Leave dead wood and leaf litter in moderation, or create designated areas, since many native bees nest in cavities or in the ground and many beneficial insects overwinter on-site.

Designing a season-long pollinator plan

A simple planting plan for a suburban Front Range yard might include:

Early spring: Willows or early-blooming serviceberry and cottonwood for the first nectar.
Mid spring: Serviceberry, chokecherry, apple/crabapple, and hawthorn.
Late spring to early summer: Mountain ash and other mid-season bloomers.
Midsummer: Linden and summer-flowering understory shrubs or perennials.
Host trees: Oaks, poplars, and native shrubs dispersed across the property to support caterpillars.

This kind of temporal staggering ensures food is available through periods when native bees are active and when migrating species pass through.

Final considerations and takeaways

Trees are long-term investments with outsized benefits for pollinators in Colorado. Choosing the right species for the site, providing continuous bloom through mixed plantings, avoiding harmful pesticides, and managing water and structure will create resilient, pollinator-rich landscapes. Even small urban yards can make a difference by planting serviceberry, chokecherry, crabapple, or a linden and by preserving native oaks and willows where possible.
Key takeaways:

Combine nectar/pollen-providing trees with host trees to support the full life cycle of pollinators.
Aim for staggered bloom times to provide season-long resources.
Match species to local elevation and soil moisture to ensure healthy, productive flowering.
Avoid insecticides during bloom and manage pests with pollinator-friendly methods.

With a thoughtful plan, Colorado homeowners, landscapers, and land managers can build tree-dominated habitats that sustain bees, butterflies, hummingbirds, and the broader web of life that depends on pollination.