Milkweed Yellow

Asclepias subulata

Light

Water

Moderate water needs. Water deeply when the upper 1–2 inches of soil dry; increase frequency during extreme heat. Not a low-water desert plant.

Size

2-4 ft tall × 2-3 ft wide

Habit

Perennial clump – rush-like

Toxicity

Toxic — Pets Humans & Livestock

Description

The name Asclepias syriaca ‘Yellow’ is not a well-established cultivar name; common milkweed normally has pinkish-purple flowers. Yellow milkweed usually refers to yellow-flowered Asclepias curassavica, such as ‘Hello Yellow’ or ‘Silky Gold’. The care below assumes yellow tropical milkweed; confirm the plant’s identity before purchasing.

Bloom Time

Spring through fall

Deciduous / Evergreen

Semi-evergreen

Special Features

Attracts Bees / Pollinators, Attracts Butterflies, Toxic (see detail)

Growth Rate

Moderate

Growth Habit

Perennial clump – rush-like

Mature Size

2-4 ft tall × 2-3 ft wide

Flower Color

Yellow-cream

Foliage Color

Gray-green

Landscape Use

Border / Bed, Container / Patio, Desert / Xeriscape, Pollinator / Wildlife Garden

Garden Style

Arizona Native, Container / Patio, Desert / Xeriscape, Pollinator / Wildlife

Soil

Amended / Rich, Sandy / Rocky, Well-Drained

Companion Plants

Autumn sage, Desert marigold, Gregg's mistflower

Toxic — Pets Humans & Livestock

Toxic to pets, livestock, and humans if ingested; milky sap is a skin/eye irritant

Care Instructions

Light: Morning sun with afternoon shade in Phoenix; avoid reflected heat from west-facing walls and pavement.

Water: Moderate water needs. Water deeply when the upper 1–2 inches of soil dry; increase frequency during extreme heat. Not a low-water desert plant.

Soil: Well-drained soil amended with compost; tolerates sandy or loamy soil. Avoid persistently saturated roots.

Mature size: Typically 2–4 feet tall and 1–3 feet wide.

Bloom: Repeated blooms from spring through fall; flowering may slow during extreme summer heat or winter cold.

Evergreen / deciduous: Evergreen to semi-evergreen without frost; frost can kill foliage and stems. May regrow from protected roots.

Growth rate: Fast during warm weather with adequate moisture.