When does common motherwort bloom in Minnesota?

Most often in July. Across 175 dated, research-grade observations of Leonurus cardiaca in Minnesota, the flowering season runs roughly June to July.

Peak July In flower 175 Examined 481 State Minnesota

Flowering 175 in flower of 481 examined

82%

90%

36%

17%

23%

Proportion of examined Leonurus cardiaca in Minnesota in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	1	too few examined
Feb	0	5	0%	0% to 43%
Mar	0	44	0%	0% to 8%
Apr	0	105	0%	0% to 4%
May	2	51	4%	1% to 13%
Jun	116	141	82%	75% to 88%
Jul	36	40	90%	77% to 96%
Aug	13	36	36%	22% to 52%
Sep	4	23	17%	7% to 37%
Oct	3	13	23%	8% to 50%
Nov	1	14	7%	1% to 31%
Dec	0	8	0%	0% to 32%

Peak flowering in Jul. Each bar is the share of Leonurus cardiaca in Minnesota observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 175 of 481 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.wt38fd.

What this is, and what it is not

This is a record of when people in Minnesota found Leonurus cardiaca in flower, not a forecast. It is computed only from observations made in Minnesota, so it is not the species’ global average dragged onto a map: the same plant flowers on different dates in different places, and that is the entire point of the page.

It will not tell you what your particular plant will do this year. Bloom time moves with the season, with altitude, and with the weather, and a warm February pulls everything forward. We publish the distribution and the sample size, and we refuse to draw a month that too few people examined.

The plant

Leonurus cardiaca

common motherwort

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Minnesota. Every record achieved iNaturalist quality grade Research, which is applied upstream at export. 10.15468/dl.wt38fd. Retrieved 2026-07-14.
World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.