When does purple salsify bloom in California?

Most often in August. Across 359 dated, research-grade observations of Tragopogon porrifolius in California, the flowering season runs roughly March to August.

Peak August In flower 359 Examined 379 State California

Flowering 359 in flower of 379 examined

86%

96%

94%

83%

100%

Proportion of examined Tragopogon porrifolius in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	2	2	too few examined
Feb	1	1	too few examined
Mar	6	7	86%	49% to 97%
Apr	136	141	96%	92% to 98%
May	156	166	94%	89% to 97%
Jun	31	33	94%	80% to 98%
Jul	10	12	83%	55% to 95%
Aug	8	8	100%	68% to 100%
Sep	4	4	too few examined
Oct	2	2	too few examined
Nov	2	2	too few examined
Dec	1	1	too few examined

Peak flowering in Aug. Each bar is the share of Tragopogon porrifolius in California 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. 359 of 379 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 6 months have fewer than 5 examined observations, so no proportion is drawn for them. 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 California found Tragopogon porrifolius in flower, not a forecast. It is computed only from observations made in California, 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

Tragopogon porrifolius

purple salsify

Sourcesevery claim on this page

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