tree

Mexican Alder

Alnus jorullensis

The Story

Plant Bio

Alnus jorullensis, commonly known as Mexican alder, is a fast-growing evergreen or semi-evergreen tree native to the high-elevation mountains of Mexico and Guatemala. It develops an erect, pyramidal to spreading form with drooping, slender branches and dark glossy green, leathery leaves that persist through mild winters.

This species is distinguished by its ability to retain its foliage in warm climates, unlike strictly deciduous alders, though it will shed leaves in response to severe winter chill. In spring, it produces long, drooping chartreuse staminate catkins alongside small, terminal clusters of female flowers.

Uses & Benefits:

Features a graceful, pyramidal canopy with drooping branches and glossy, leathery foliage that remains green year-round in mild climates.

Serves as an effective windbreak and stabilizes wet soils or stream banks to prevent erosion.

Fixes atmospheric nitrogen through Frankia root symbiosis, enriching poor soils, and provides nesting sites for songbirds.

Essentials

At a Glance

Plant Type

Tree

Height

984"

Width

787"

Light

Full Sun, Partial Sun

Zones

7, 8, 9, 10

Water

High

Humidity

High

Lifespan

Moderate

Native To

Central America (Mexico and Guatemala)

Toxicity

Non-toxic

Bloom period

Spring

In flower about 3 months of the year

Planting

How to Grow

Select a planting site in full sun to partial shade with ample space for the mature canopy and root spread.
Dig a hole twice as wide as the root ball and of equal depth, ensuring the soil is moist or wet.
Position the tree so the root flare sits level with or slightly above the surrounding soil grade.
Backfill with native soil, water deeply to settle, and apply a thick layer of organic mulch to retain moisture.

Pro Tip

Plant this tree at least 30 feet away from sewer lines, water pipes, and foundations, as the highly aggressive root system actively seeks out moisture and can easily penetrate subterranean infrastructure.

Keep It Thriving

Care Guide

Do

Provide regular deep watering during dry summer periods to support the tree's high moisture requirements.
Plant in areas with wet soil or poor drainage where other tree species fail to establish.
Protect young trees from severe, icy winter winds which can damage foliage and kill tender stems.

Don't

Do not plant near sewer pipes, septic fields, drains, or concrete foundations.
Do not apply nitrogen-heavy fertilizers, as the tree hosts symbiotic bacteria that fix their own nitrogen.
Do not prune heavily into old, leafless wood, which results in slow and patchy regrowth.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Mulch
Pest Check
Propagate
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Specimen TreeWindbreakErosion ControlWetland Restoration

Companion Plants

Carex stricta Cornus sericea Sambucus nigra

Multiply

Propagation Methods

Good to Know

Common Questions

Mexican Alder questions

What zones can Mexican Alder grow in?

Mexican Alder is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does Mexican Alder bloom?

Mexican Alder typically blooms in spring through spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Mexican Alder need full sun?

Mexican Alder does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.