Milkweed in California
California holds more milkweed species than any other western state: narrowleaf in the Central Valley, heartleaf and California milkweed in the foothills, desert and rush milkweed in the south. Its coastal groves host the entire overwintering western monarch population. Tropical milkweed is a serious problem here and should not be planted.
The best milkweed to plant in California
Native to the state, garden-worthy and useful to monarchs. Start here if you are planting rather than identifying.
All milkweed species in California
| Species | Height | Flower | Bloom | Soil | Monarch |
|---|---|---|---|---|---|
| Showy Milkweed Asclepias speciosa |
2 ft–5 ft | pink, rose | May to August | Average / Dry | |
| Narrowleaf Milkweed Asclepias fascicularis |
2 ft–4 ft | white, pink, green | May to September | Dry / Average | |
| Heartleaf Milkweed Asclepias cordifolia |
1 ft–3 ft | maroon, purple | May to July | Dry | |
| California Milkweed Asclepias californica |
1 ft–3 ft | maroon, purple | April to July | Dry | |
| Rush Milkweed Asclepias subulata |
2 ft–6 ft | cream, white | nearly year-round in frost-free areas | Dry | |
| Woollypod Milkweed Asclepias eriocarpa |
2 ft–4 ft | cream, white | May to August | Dry | |
| Desert Milkweed Asclepias erosa |
2 ft–5 ft | cream, yellow | April to September | Dry | |
| Whitestem Milkweed Asclepias albicans |
3 ft–10 ft | cream, white | January to May and November to December | Dry | |
| Balloon Plant Gomphocarpus physocarpus |
3 ft–6 ft | white, cream | May to October | Average | |
| Tropical Milkweed Asclepias curassavica |
2 ft–4 ft | red, orange, yellow | nearly year-round in frost-free areas | Average | |
| Woolly Milkweed Asclepias vestita |
1 ft–3 ft | cream, yellow | April to July | Dry | |
| Giant Milkweed Calotropis procera |
6 ft–12 ft | white, purple | nearly year-round in frost-free areas | Dry | |
| Pallid Milkweed Asclepias cryptoceras |
4 in–1 ft | cream, pink | April to June | Dry | |
| Serpentine Milkweed Asclepias solanoana |
4 in–10 in | cream, pink | May to July | Dry |
Rare or protected in part of this range: Serpentine Milkweed. Do not collect seed or plants from wild populations of these species.
Not native but naturalised here: Balloon Plant, Tropical Milkweed, Giant Milkweed. Because California has mild winters, tropical milkweed can sustain year-round monarch breeding and raise OE parasite loads, so plant a native instead.
Planting milkweed in California
Sow seed outdoors in October to December, so the seed uses winter rain. Winter then supplies the cold-moist stratification most milkweed seed needs, and germination happens naturally as the soil warms. If you have missed that window, chill seed in the refrigerator for 30 days and sow after your last frost. The full method is here.
California spans USDA zones 5a–11a, so check the zone range on each species page before committing. Match the species to your site rather than the other way round: dry, sunny and poor suits butterfly weed and the whorled species; a damp spot suits swamp milkweed; shade suits very few milkweeds at all.
Plant at least ten stems in one group rather than scattering them, because female monarchs find dense patches far more readily. Add late-season nectar such as goldenrod and asters so the fall migratory generation has fuel as well as host plants. How to lay out a monarch garden.
Where to buy milkweed in California
Start with California Native Plant Society. State native plant societies run the plant sales worth going to: locally grown, untreated stock, at a few dollars a plant, sold by people who can tell you where to put it.
In California
California native plant non-profit with a nursery, a seed program and a well-known plant sale.
Independent California native seed house.
Independent California native nursery with unusually detailed species notes.
Independent southern California native plant nursery.
Independent Bay Area nursery growing local-provenance natives.
Elsewhere in the pacific
Independent Portland nursery growing Pacific Northwest natives.
Ships to you
One of the widest milkweed seed and bare-root ranges anywhere, with germination codes listed for every species.
Long-established independent nursery specializing in Midwestern natives.
Independent seed producer supplying restoration-scale native seed by the pound.
Family-run native seed producer for the eastern and central states.
Family-run Texas seed house focused on regional ecotypes.
These favor independent nurseries and non-profits over chain garden centers, which mostly stock unlabeled tropical milkweed and often cannot tell you whether it has been treated with neonicotinoids. Search the full directory by ZIP code.
Milkweed in California: common questions
What milkweed is native to California?
11 milkweed species are recorded in California, including Showy Milkweed (Asclepias speciosa), Narrowleaf Milkweed (Asclepias fascicularis), Heartleaf Milkweed (Asclepias cordifolia), California Milkweed (Asclepias californica). The full list is on this page.
What is the best milkweed to plant in California?
Showy Milkweed, Narrowleaf Milkweed, Heartleaf Milkweed are the best combination of native, available and garden-worthy for California. Showy Milkweed is the easiest to start with.
When should I plant milkweed seed in California?
Sow outdoors in October to December, so the seed uses winter rain, so winter provides the cold stratification the seed needs. If you have missed that window, stratify seed in the refrigerator for 30 days and sow in spring after the last frost.
Does milkweed grow wild in California?
Yes. 14 species occur in California, typically on roadsides, field margins, prairie remnants and along watercourses. California holds more milkweed species than any other western state: narrowleaf in the Central Valley, heartleaf and California milkweed in the foothills, desert and rush milkweed in the south.
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Milkweed in California. Retrieved DATE, from https://milkweedusa.com/states/california/
"Milkweed in California." Milkweed USA, 2026, https://milkweedusa.com/states/california/. Accessed DATE.
Milkweed USA. "Milkweed in California." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/states/california/.
@misc{milkweedusa_statescalifornia,
title = {Milkweed in California},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/states/california/},
note = {Accessed DATE}
}