Madrean Archipelago (Archipiélago madrense) is a region straddling the national border in southeast Arizona, southwest New Mexico, and northern Sonora, significant as both a barrier and bridge between the Rocky Mountains and the Sierra Madre Occidental, and characterized by "sky islands" of basins and ranges with varying elevations, dry subtropical climate, and diverse vegetation including semi-desert grasslands, shrub steppe, and Madrean oak-juniper woodlands.
Zone
Coastal
Common Name
Madrean Archipelago
CEC Level III Code
12.1.1
CEC Level II Code
12.1 Western Sierra Madre Piedmont
Overview
Region facts
| Category | Details |
|---|---|
| Aliases | Madrean Archipelago |
| Geographic Range | The Madrean Archipelago straddles the national border in southeast Arizona, southwest New Mexico, and northern Sonora, serving as an ecological barrier and bridge between the Rocky Mountains and the Sierra Madre Occidental. |
| Climate Snapshot | The Madrean Archipielago ecoregion has a dry, subtropical to mid-latitude steppe climate with hot summers, mild winters, a mean annual temperature ranging from 7°C to 19°C, and a mean annual precipitation of 421 mm, much of which occurs during July to September thunderstorms. |
| Terrain Profile | The terrain consists of basins and ranges, or "sky islands," with medium to high local relief, and elevations ranging from 800 to more than 3,000 meters. |
| Vegetation Cover | The Madrean Archipelago features semi-desert grasslands and shrub steppe in the basins, Madrean oak-juniper woodlands on mountain slopes, and ponderosa pine, white pine, and Douglas fir at higher elevations. |
| Wildlife Habitat | The Madrean Archipelago is home to diverse wildlife, including mule deer, cougars, jaguars, coyotes, bobcats, various birds of prey like the Cooper's hawk, and reptiles such as the western diamondback rattlesnake and gila monster. |
Eco snapshot
The Madrean Archipelago features semi-desert grasslands and shrub steppe in the basins, Madrean oak-juniper woodlands on mountain slopes, and ponderosa pine, white pine, and Douglas fir at higher elevations.
The Madrean Archipelago is home to diverse wildlife, including mule deer, cougars, jaguars, coyotes, bobcats, various birds of prey like the Cooper’s hawk, and reptiles such as the western diamondback rattlesnake and gila monster.
Seasonal timing
Yearly needs
What pollinators need throughout the year, and what to do about it.
| Season | What pollinators need most | What you can do |
|---|---|---|
| Late winter/early spring | Early nectar/pollen; safe shelter as temperatures swing | Plant/maintain early-blooming natives; avoid “spring clean-up” that removes shelter |
| Spring | Expanding bloom variety; nesting sites | Add 2–3 spring bloomers; leave some bare soil; keep a shallow water dish with stones |
| Summer | Reliable flowers through heat; shade and water nearby | Plant heat-tough bloomers; water deeply (not daily sprinkles); keep blooms going in clumps |
| Late summer/fall | “Finish-line” nectar/pollen; seed/cover for overwintering | Add late bloomers; let some plants go to seed; reduce trimming until later |
| Winter or Dry Season | Shelter; undisturbed nesting areas | Leave stems/leaves; avoid pesticides; plan next season’s bloom sequence |
Keystone plants
Mix early, mid, and late bloomers so pollinators always find food.
Seed mix concept
Spring starter: early bloomers that help pollinators ramp up after the cool season
Summer bridge: heat-tough flowers that keep nectar/pollen available through the warmest period
Fall finisher: late bloomers that provide crucial fuel before the off-season
What You Can Do
Turn this knowledge into action. Whether you plant a single pot or a whole garden, you are building a vital bridge for local biodiversity.
Join the movement to restore our shared habitats.
Native plants
Agaves are bold, sculptural succulents that store water in thick leaves and thrive in bright, dry spots. Their flowers can be a big seasonal draw for pollinators when plants are mature and in bloom.
Creosote bush (genus Larrea) is a tough, sun-loving shrub known for its small yellow flowers and resin-scented leaves. It’s best for dry, open spaces where you want a low-water plant that can still offer nectar and pollen when in bloom.
Desert mallows (globe mallows) are tough, sun-loving plants in the genus Sphaeralcea that bring warm-colored blooms and easy pollinator value to dry, low-fuss gardens and containers.
Desert marigolds are sunny, daisy-like wildflowers in the genus Baileya that bring bright color and steady nectar to warm, open garden spots.
Mesquites are tough, drought-adapted trees in the genus Prosopis that can add shade and seasonal flowers to dry landscapes while offering nectar and pollen for a range of pollinators.
Ocotillo is a dramatic desert shrub in the genus Fouquieria, known for tall, wand-like stems and bright flower clusters that can be a valuable nectar stop when in bloom.
Organ pipe & relatives are columnar cacti in the genus Stenocereus, grown for their bold, upright stems and showy blooms that can offer nectar and pollen when flowers are open.
Penstemons (beardtongues) are hardy, flower-filled wildflowers that bring bright color and steady nectar to gardens and containers, especially in sunny spots with well-drained soil.
Phacelias are easygoing wildflowers in the genus Phacelia, known for their nectar-rich blooms that can bring lots of pollinator activity to gardens, schoolyards, and even containers.
Prickly pears are tough, sun-loving cacti (genus Opuntia) with bright blooms that can offer nectar and pollen when in flower. They’re best for warm, bright spots and gardeners who want a low-water plant with big character.
Prickly poppies (genus Argemone) are bold, spiny wildflowers with papery blooms that can add bright color and nectar to sunny, low-fuss garden spots.
Saguaros are iconic desert cacti that grow slowly, live a long time, and offer seasonal flowers that can support pollinators when grown in the right conditions.
Wild buckwheats (genus Eriogonum) are tough, long-blooming western native wildflowers that can turn dry, sunny spots into reliable pollinator stops.
Yucca is a group of bold, architectural plants with spiky leaves and tall flower stalks that can add structure to sunny gardens and containers. Many yuccas are tough once established and can be a low-fuss way to offer nectar to visiting pollinators when in bloom.
Pollinators
Adults visit flowers for nectar and can move pollen between blooms; their presence is a sign of diverse, functioning habitats.
Bumble bees are important pollinators of many wildflowers and garden plants, helping ecosystems and food crops reproduce.
Adults can move pollen between blooms, and their presence can signal how healthy local plant communities are.
They move pollen between flowers while feeding, helping wild plants and many garden plants set seed and fruit.
Adults visit flowers for nectar and pollen, and many species’ larvae help keep plant-eating pests in check.
They can move pollen between flowers while feeding on nectar, especially for blooms that open or scent up in the evening.
They move pollen between flowers while feeding, helping many plants reproduce.
They move pollen between flowers while foraging, helping many wild plants and garden plants set seed and fruit.
They move pollen between flowers as they feed, supporting seed and fruit set in many wild plants and some crops.
They move pollen between flowers over long distances, helping some plants set fruit and seed.
They move pollen between flowers while foraging, helping many wild plants and garden plants set seed and fruit.
They move pollen between flowers over long distances and help many plants set fruit and seed.
They can move pollen while drinking nectar, and they also help control many plant-eating insects.
Many small moths move pollen while feeding on nectar, supporting wild plants and garden blooms—especially in the evening and at night.
Many adults visit flowers and can move pollen between blooms, while also helping control some garden pests.
Many adults visit flowers for nectar and can move pollen between blooms while feeding.
They help move pollen between flowers in gardens, parks, and natural areas, supporting seed and fruit production.
