Garden hybrid

This is a garden hybrid, bred from more than one wild species, so it has no single species page of its own.

95 other cultivars

shrub

Formosa Azalea

Rhododendron x hybrida 'Formosa'

The Story

Plant Bio

Rhododendron x hybrida comprises evergreen ornamental shrubs derived from Asian parent species, cultivated for their mass spring flower displays. These plants develop shallow, fibrous root systems that require highly acidic, organically rich soil with rapid drainage.

'Formosa' is a vigorous, broad-spreading Southern Indica cultivar that reaches up to ten feet in height with dark green evergreen leaves. In spring, it produces broad clusters of single rose-purple flowers up to four inches across, marked by a deep red throat blotch.

Uses & Benefits:

Produces vibrant magenta-purple flowers in spring against thick glossy evergreen leaves.

Forms a dense evergreen structural hedge or mass background planting in acidic shade.

Provides early spring nectar for hummingbirds, butterflies, and native bees.

Garden hybrid

Bred from more than one wild species, so it has no species page of its own.

Essentials

At a Glance

Plant Type

Shrub

Height

118"

Width

118"

Light

Partial Sun, Shade

Zones

8, 9, 10

Water

Moderate

Humidity

High

Lifespan

Perennial

Native To

Asia (ancestral parents)

Toxicity

Toxic to humans, cats, dogs, and horses

Bloom period

Spring

In flower about 3 months of the year

Planting

How to Grow

Select a planting location offering partial shade or filtered light protected from harsh afternoon sun.
Amend native soil with composted pine bark or leaf mold to achieve an acidic pH between 4.5 and 5.5.
Set the top of the root ball two inches above ground level to ensure adequate oxygenation and root drainage.
Apply a three-inch layer of organic pine-needle mulch around the base, keeping it clear of direct stem contact.

Pro Tip

Plant the shallow root ball slightly elevated above the soil line in mounded organic matter; cutting into old bare wood prevents new bud sprouting.

Keep It Thriving

Care Guide

Do

Maintain consistent moisture across the shallow fibrous root zone.
Prune lightly immediately after spring bloom finishes.
Feed with an acid-formulation slow-release fertilizer in early spring.

Don't

Do not plant in heavy, poorly drained clay or saturated standing water.
Do not prune into thick, leafless wood as it fails to regenerate foliage.
Do not plant the crown deeper than the surrounding soil surface.

Seasonal Care Calendar

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

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Foundation PlantingHedgeMass PlantingUnderstorySpecimen/Focal Point

Companion Plants

Camellia japonica Heuchera americana Acer palmatum Pieris japonica

Multiply

Propagation Methods

Good to Know

Common Questions

Formosa Azalea questions

What zones can Formosa Azalea grow in?

Formosa Azalea is hardy in USDA Zones 8–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Formosa Azalea deer resistant?

Not reliably. Deer may browse Formosa Azalea, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Formosa Azalea bloom?

Formosa Azalea 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 Formosa Azalea need full sun?

Formosa Azalea does best in part shade.