Wildflower/Perennial · Sonoran native
Pineleaf Milkweed
Asclepias linaria · Apocynaceae
Also called: Pine-needle Milkweed, Pineneedle Milkweed, Needleleaf Milkweed, Pinleaf Milkweed
Pineleaf Milkweed (Asclepias linaria) is a very low-water wildflower/perennial native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun.
Pineleaf Milkweed at a glance
- Water use
- Very Low (established)
- Sun
- Full sun; thrives in hot, exposed, well-drained sites.
- Mature size
- 2-4 ft H x 2-3 ft W (rounded evergreen subshrub)
- Growth rate
- Slow to moderate.
- Bloom
- Small creamy white to pale yellowish flowers in rounded clusters; followed by slender erect seed pods., Spring through fall (roughly March-October), blooming intermittently with warm weather and monsoon moisture.
- Cold hardiness
- Cold hardy to about 15-20 F (USDA zones 8-11); hardy in most of Tucson, may suffer tip damage in hard frosts.
- Soil
- Well-drained sandy, gravelly, or rocky desert soils; tolerates poor and alkaline soils. Sharp drainage is essential.
- Native range
- Native to the Sonoran Desert of Arizona and northern Mexico (Sonora, Baja California) and adjacent arid regions.
- Best used as
- Accent/specimen subshrub, Butterfly and pollinator garden (monarch/queen larval host), Desert/xeriscape garden, Mixed native shrub plantings, Foundation and border plantings, Wildlife habitat garden
- Wildlife
- Important larval host plant for monarch and queen butterflies; nectar attracts butterflies, bees, and other pollinators. Like other milkweeds, supports milkweed-specialist insects.
- Toxicity
- Toxic if ingested; like all milkweeds, contains cardiac glycosides in its milky sap that are poisonous to people, pets, and livestock, and the sap can irritate skin and eyes.
How to grow Pineleaf Milkweed in Tucson & the low desert
Watering
Very drought tolerant once established; water deeply and sparingly. Occasional deep irrigation (every 2-3 weeks) in extreme summer heat keeps it lush, but it tolerates long dry spells. Avoid overwatering, which causes root rot.
Fertilizer & nutrients
No fertilizer needed; adapted to lean desert soils. Fertilizing is unnecessary.
Pruning & care
Minimal pruning; lightly shape or remove frost-damaged tips in spring. Avoid hard shearing — let it keep its natural soft, rounded, fine-textured form.
Notes
Evergreen, fine-textured native milkweed with soft pine-needle-like foliage forming a neat rounded subshrub — more shrub-like and ornamental than most milkweeds. Excellent low-water Sonoran Desert host plant for monarch and queen butterflies and an attractive year-round accent. Now placed in family Apocynaceae (formerly Asclepiadaceae). Provide sharp drainage and restrained water.
Sources: Arizona-Sonora Desert Museum; University of Arizona Cooperative Extension; AMWUA Landscape Plants for the Arizona Desert; Tohono Chul; Tucson Botanical Gardens