When does common woolly sunflower bloom in Oregon?

Most often in June. Across 677 dated, research-grade observations of Eriophyllum lanatum in Oregon, the flowering season runs roughly June to July.

Peak June In flower 677 Examined 1,042 State Oregon

Flowering 677 in flower of 1,042 examined

15%

72%

91%

80%

40%

11%

Proportion of examined Eriophyllum lanatum in Oregon in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	10	0%	0% to 28%
Feb	1	11	9%	2% to 38%
Mar	1	50	2%	0% to 11%
Apr	12	80	15%	9% to 24%
May	210	293	72%	66% to 77%
Jun	300	329	91%	88% to 94%
Jul	133	166	80%	73% to 85%
Aug	16	40	40%	26% to 55%
Sep	3	27	11%	4% to 28%
Oct	1	21	5%	1% to 23%
Nov	0	5	0%	0% to 43%
Dec	0	10	0%	0% to 28%

Peak flowering in Jun. Each bar is the share of Eriophyllum lanatum in Oregon 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. 677 of 1,042 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 Oregon found Eriophyllum lanatum in flower, not a forecast. It is computed only from observations made in Oregon, 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

Eriophyllum lanatum

common woolly sunflower

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Oregon. 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.