The Hudson Valley Bioregional Guide

A bioregion is a place defined not by political borders but by the shape of its land, the flow of its waters, and the communities of plants, animals, and people that share it. The Hudson Valley bioregion stretches roughly 150 miles from the tidewater estuary near New York Harbor north to the foothills of the Adirondacks, and from the Catskill Escarpment east across the river to the Taconic Highlands on the Massachusetts and Connecticut border.

Within this larger region, the Hudson Valley Pollinator Project works in what ecologists call the Lower Hudson and Wallkill sub-basins — centered on Orange County, New York, and reaching into Sullivan, Ulster, Rockland, Dutchess, and Putnam counties as well as northern New Jersey and northwestern Connecticut. Because more than 20 million people live within a two-hour drive, the choices made on lawns, farms, vineyards, roadsides, and preserves here have an outsized effect on the pollinators of the Northeast.

The pollinator habitats of the Hudson Valley sit on top of one of the most complicated pieces of geology in eastern North America. Four major landforms shape what grows where:

• The Hudson Highlands. A rugged belt of billion-year-old Precambrian gneiss and granite that pinches the Hudson River at Bear Mountain and Storm King. Thin, acidic soils here support oak-heath forests, blueberry barrens, and rocky outcrops where Andrena mining bees nest.
• The Wallkill and Black Dirt Region. A drowned glacial lake bed in western Orange County that left behind deep, black, muck soils — some of the most fertile in the world. These wet meadows historically supported vast expanses of swamp milkweed (Asclepias incarnata), Joe-Pye weed, and boneset.
• The Shawangunk Ridge. White quartzite cliffs and pitch pine barrens that host specialist pollinators tied to blueberry, huckleberry, and sheep laurel.
• The Appalachian Plateau & Catskill Foothills. Higher, cooler, wetter uplands with sugar maple, black cherry, and rich cove forests dense in spring ephemerals.

Warwick Valley — where the Pollinator Project is headquartered — sits in the transition zone between the Highlands and the Wallkill lowlands. That ecotone is why a single day of field work here can turn up ridgetop lupine bees and lowland marsh butterflies within a few miles of each other.

Water writes the story of pollinator habitat. The Hudson Valley bioregion drains through several major sub-watersheds, each with its own pollinator communities:

Wetlands are disproportionately valuable: they cover a small fraction of the landscape but support a large share of native bee, butterfly, and moth diversity. Protecting even a quarter acre of wet meadow does more for pollinators than a full acre of mowed lawn.

The U.S. EPA divides our area into two Level III ecoregions — the Northeastern Highlands and the North Atlantic Coastal Plain / Northeastern Coastal Zone — with a mosaic of Level IV subregions inside them. In practical, on-the-ground terms, we work across seven recurring plant communities:

The 2023 USDA Plant Hardiness update placed most of Orange County in Zone 6b (−5°F to 0°F winter minimum), with valley bottoms warming to 7a and Highland ridgetops still 6a. The Hudson Valley has warmed roughly 2.5°F since 1970, and the frost-free season has lengthened by about 10 days. Practical implications for pollinator gardeners:

• Native plant bloom times are shifting earlier — a "spring succession" garden should now start with skunk cabbage and pussy willow in February.
• Southern species like American holly and sweetbay magnolia are increasingly viable in Zone 7a valley sites.
• Drought spells are more common; deep-rooted natives (little bluestem, butterfly milkweed) outperform shallow lawn grass.
• Warm, wet Octobers extend fall goldenrod and aster nectar for migrating monarchs.

The honey bee gets the headlines, but it is a European livestock animal. New York State is home to roughly 450 native bee species, along with hundreds of butterflies, thousands of moths, and dozens of pollinating flies, beetles, and wasps. A representative sample from our bioregion:

A pollinator garden must offer two things: nectar and pollen for adult insects, and host plants where caterpillars can feed. The following list is intentionally drawn from species that are native to the Hudson Valley bioregion — not "wildflower mixes" of Eurasian escapees.

For deeper dives into individual species, see our Native Plant Field Guide blog.

Pollinators need continuous bloom from March through October. A garden with everything flowering in July but nothing in April or September starves the queens who start and end each colony's year. Plant across every column:

Nectar plants are only half the equation. Native pollinators also need places to nest, overwinter, and find shelter from pesticides. Every property, no matter how small, can host one or more of the following:

Some of the most common plants in Hudson Valley yards actively harm pollinators — either by displacing native host plants, offering false-food to specialists, or forming monocultures where nothing else can grow. Priority removals:

• Butterfly bush (Buddleja davidii) — nectar-only; hosts no native caterpillars; escapes to riverbanks.
• Japanese barberry (Berberis thunbergii) — dense thickets, tick amplifier, hosts almost no Lepidoptera.
• Japanese knotweed (Reynoutria japonica) — riparian monoculture; smothers native nectar plants.
• Bush honeysuckles (Lonicera spp.) — early leaf-out shades out spring ephemerals.
• Multiflora rose (Rosa multiflora) — Old-field colonizer that replaces native shrub-swamp habitat.
• Autumn olive (Elaeagnus umbellata) — nitrogen-fixer that alters soil chemistry.
• Garlic mustard (Alliaria petiolata) — poisons soils used by native spring ephemerals.
• Tree of heaven (Ailanthus altissima) — host of the invasive spotted lanternfly.

• Xerces Society — Pollinators of Native Plants, Heather Holm
• Douglas Tallamy — Nature's Best Hope and The Nature of Oaks
• New York Natural Heritage Program — Ecological Communities of New York State
• Cornell Cooperative Extension of Orange County — home horticulture bulletins
• Hudson River Estuary Program — Trees for Tribs riparian planting guides
• USDA NRCS — Northeast Pollinator Habitat Planting Guide
• New York Flora Atlas — county-level native plant distribution

This guide is a living document. If you have local corrections, species sightings, or additions specific to your Hudson Valley property, get in touch.