Spring · month 5 of 12
Milkweed and monarchs in May
Milkweed comes up, monarchs arrive
53species that can be in flower
30at peak bloom
50of them native
Springseason
Where the monarchs are
The second generation spreads across the Midwest, the Great Lakes and the mid-Atlantic. This is when most of the country sees its first monarch of the year.
What to do this month
- Plant out after your last frost. Water in well, then weekly for six weeks, then stop.
- Be patient with butterfly weed. It emerges four to six weeks after everything else and looks dead until it does not.
- Direct-sow into prepared bare soil if you missed fall.
- Start checking leaf undersides for eggs: pale, ribbed and the size of a pinhead.
What to look for
- Purple milkweed and clasping milkweed flowering in the East.
- Showy milkweed in bud along western irrigation ditches.
- First monarch eggs in the Midwest.
North and south
Northern gardeners can plant out from mid-May in most years. In the South, growth is already well ahead and heat is becoming the limiting factor.
In flower in May
53 species can be in flower somewhere in the country this month, 30 of them at peak. Natives are listed first.
| Species | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Antelope Horns | Not in bloom in January | Not in bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Green Antelopehorn | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Pinewoods Milkweed | Not in bloom in January | Not in bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Zizotes Milkweed | Not in bloom in January | Not in bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | Peak bloom in September | In bloom in October | Not in bloom in November | Not in bloom in December |
| Clasping Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | Not in bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| California Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Heartleaf Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | Not in bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Desert Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | In bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Rush Milkweed | In bloom in January | In bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | Peak bloom in September | Peak bloom in October | In bloom in November | In bloom in December |
| Fourleaf Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | Not in bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Velvetleaf Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Woolly Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Pineneedle Milkweed | Not in bloom in January | Not in bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | Peak bloom in September | In bloom in October | Not in bloom in November | Not in bloom in December |
| Bract Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Emory’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | Peak bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Curtiss’ Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | In bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Feay’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | In bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Pallid Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Dwarf Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Longhood Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Michaux’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Longleaf Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Mead’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | Not in bloom in April | Peak bloom in May | Peak bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Mojave Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Ruth’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Prostrate Milkweed | Not in bloom in January | Not in bloom in February | In bloom in March | Peak bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | In bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Savannah Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | Peak bloom in June | In bloom in July | In bloom in August | In bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Wheel Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Eastwood’s Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | Not in bloom in April | Peak bloom in May | Peak bloom in June | Not in bloom in July | Not in bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
| Tufted Milkweed | Not in bloom in January | Not in bloom in February | Not in bloom in March | In bloom in April | Peak bloom in May | In bloom in June | In bloom in July | In bloom in August | Not in bloom in September | Not in bloom in October | Not in bloom in November | Not in bloom in December |
in bloom peak bloom
See the full bloom chart for all 72 species.
May questions
What milkweed blooms in May?
53 milkweed species can be in flower somewhere in the United States during May, with Antelope Horns, Green Antelopehorn, Pinewoods Milkweed, Zizotes Milkweed at peak. Bloom times shift several weeks later as you move north.
What are monarch butterflies doing in May?
The second generation spreads across the Midwest, the Great Lakes and the mid-Atlantic. This is when most of the country sees its first monarch of the year.
What should I do in the milkweed garden in May?
Plant out after your last frost. Water in well, then weekly for six weeks, then stop. Be patient with butterfly weed. It emerges four to six weeks after everything else and looks dead until it does not. Direct-sow into prepared bare soil if you missed fall.
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APA
Milkweed USA. (2026). Milkweed and monarchs in May. Retrieved DATE, from https://milkweedusa.com/calendar/may/
MLA
"Milkweed and monarchs in May." Milkweed USA, 2026, https://milkweedusa.com/calendar/may/. Accessed DATE.
Chicago
Milkweed USA. "Milkweed and monarchs in May." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/calendar/may/.
BibTeX
@misc{milkweedusa_calendarmay,
title = {Milkweed and monarchs in May},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/calendar/may/},
note = {Accessed DATE}
}