Native & adapted

Yellow oleander

Cascabela thevetia

A glossy evergreen screen or small tree with yellow trumpet flowers—beautiful and heat tolerant, but dangerously toxic in every part.

Arid adaptedEvergreenFloweringHighly toxic

Landscape layersUnderstory · Hedging

Mature size

8–15 ft tall × 6–12 ft wide

Climate fit

Urban core · USDA 9b–10a · Valley suburbs · USDA 9a–9b · Desert outskirts · USDA 8b–9b

Special categories

ARID ADAPTED

Hardiness guidance

USDA zones 9b–11; frost can damage exposed growth

Right plant, right place

Will Yellow oleander grow at your Arizona property?

All parts are highly toxic if eaten. Do not plant where children, pets, livestock, or falling seeds create an exposure risk; wear protection when pruning.

Best regional fit: Urban core · USDA 9b–10a, Valley suburbs · USDA 9a–9b, Desert outskirts · USDA 8b–9b.

Light

Sun exposure

Full sun for dense form and strong flowering.

Water

Irrigation

Low once established. Deep, separated irrigation supports flowering without keeping the root zone wet.

Choose the actual plant, not only the label

Cultivars & selections

Yellow- and peach-flowered forms exist, but toxicity is unchanged. This is a risk-based site decision, not simply a flower-color choice.

Yellow-flowered form

Cascabela thevetia

Mature size8–15 ft tall × 6–12 ft wide

Best forControlled-access ornamental screens

The classic golden-yellow form. Every plant part, including seed, sap, and foliage, is poisonous.

Peach / apricot-flowered form

Cascabela thevetia selection

Mature size8–15 ft tall × 6–12 ft wide

Best forWarm-color ornamental accents

Flower color varies, but mature size, management, and severe toxicity remain essentially the same.

Planting & stewardship

How to help Yellow oleander thrive

1
Evaluate poisoning risk before planting; choose a safer species if access cannot be controlled.
2
Wear gloves and eye protection for pruning and keep sap off skin.
3
Collect fallen fruit and seed where people or animals could reach them.
4
Train as a shrub or small tree with selective cuts rather than repeated shearing.

Read the horticultural reference ↗