Milkweed in Iowa
Iowa produces a disproportionate share of the eastern monarch population, almost entirely from roadside plantings, CRP acres and cemetery prairies in a landscape that is otherwise more than 85 percent cultivated. The state’s integrated roadside vegetation management program is a national model.
The best milkweed to plant in Iowa
Native to the state, garden-worthy and useful to monarchs. Start here if you are planting rather than identifying.
All milkweed species in Iowa
| Species | Height | Flower | Bloom | Soil | Monarch |
|---|---|---|---|---|---|
| Swamp Milkweed Asclepias incarnata |
3 ft–5 ft | pink, rose, white | June to September | Wet / Average | |
| Butterfly Weed Asclepias tuberosa |
1 ft–3 ft | orange, yellow, red | May to September | Dry / Average | |
| Showy Milkweed Asclepias speciosa |
2 ft–5 ft | pink, rose | May to August | Average / Dry | |
| Prairie Milkweed Asclepias sullivantii |
2 ft–4 ft | pink, rose | June to July | Average / Wet | |
| Purple Milkweed Asclepias purpurascens |
2 ft–4 ft | purple, magenta | May to July | Average / Dry | |
| Poke Milkweed Asclepias exaltata |
3 ft–6 ft | white, green | June to July | Average | |
| Common Milkweed Asclepias syriaca |
3 ft–6 ft | pink, mauve, white | June to August | Dry / Average | |
| Whorled Milkweed Asclepias verticillata |
1 ft–2.5 ft | white, green | June to September | Dry / Average | |
| Clasping Milkweed Asclepias amplexicaulis |
1.5 ft–3 ft | pink, green, mauve | May to July | Dry | |
| Fourleaf Milkweed Asclepias quadrifolia |
1 ft–2 ft | pink, white | May to June | Dry / Average | |
| Oval-leaf Milkweed Asclepias ovalifolia |
8 in–1.7 ft | white, green | June to July | Dry / Average | |
| Green Comet Milkweed Asclepias viridiflora |
1 ft–3 ft | green | May to August | Dry | |
| Slimleaf Milkweed Asclepias stenophylla |
1.5 ft–3.3 ft | cream, green | June to August | Dry | |
| Tall Green Milkweed Asclepias hirtella |
2 ft–4 ft | green, white | June to August | Dry / Average | |
| Mead’s Milkweed Asclepias meadii |
1 ft–2 ft | green, cream | May to June | Average / Dry | |
| Woolly Milkweed Asclepias lanuginosa |
4 in–1 ft | cream, green | May to June | Dry |
Rare or protected in part of this range: Mead’s Milkweed, Woolly Milkweed. Do not collect seed or plants from wild populations of these species.
Planting milkweed in Iowa
Sow seed outdoors in late October to early December. 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.
Iowa spans USDA zones 4b–6a, 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 Iowa
Start with Iowa 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 Iowa
Independent prairie seed and plant nursery in north-east Iowa.
Elsewhere in the midwest
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 nursery growing Missouri-provenance natives.
Independent grower supplying Midwestern restoration projects.
Independent seed supplier with a broad milkweed range in small packets.
Independent Upper Midwest native seed producer.
Family-run Ozarks native seed producer.
Ships to you
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.
Small independent mail-order nursery for eastern natives.
Ships plants from a network of independent native growers, so you can buy small quantities from wholesale nurseries.
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 Iowa: common questions
What milkweed is native to Iowa?
16 milkweed species are recorded in Iowa, including Swamp Milkweed (Asclepias incarnata), Butterfly Weed (Asclepias tuberosa), Showy Milkweed (Asclepias speciosa), Prairie Milkweed (Asclepias sullivantii). The full list is on this page.
What is the best milkweed to plant in Iowa?
Swamp Milkweed, Butterfly Weed, Showy Milkweed are the best combination of native, available and garden-worthy for Iowa. Swamp Milkweed is the easiest to start with.
When should I plant milkweed seed in Iowa?
Sow outdoors in late October to early December, 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 Iowa?
Yes. 16 species occur in Iowa, typically on roadsides, field margins, prairie remnants and along watercourses. Iowa produces a disproportionate share of the eastern monarch population, almost entirely from roadside plantings, CRP acres and cemetery prairies in a landscape that is otherwise more than 85 percent cultivated.
Cite this page
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Milkweed USA. (2026). Milkweed in Iowa. Retrieved DATE, from https://milkweedusa.com/states/iowa/
"Milkweed in Iowa." Milkweed USA, 2026, https://milkweedusa.com/states/iowa/. Accessed DATE.
Milkweed USA. "Milkweed in Iowa." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/states/iowa/.
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title = {Milkweed in Iowa},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/states/iowa/},
note = {Accessed DATE}
}