When does seaside daisy bloom in California?

Most often in May. Across 914 dated, research-grade observations of Erigeron glaucus in California, the flowering season runs roughly February to November.

Peak May In flower 914 Examined 974 State California

Flowering 914 in flower of 974 examined

78%

83%

95%

97%

99%

98%

95%

91%

94%

91%

73%

Proportion of examined Erigeron glaucus in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	31	40	78%	63% to 88%
Feb	34	41	83%	69% to 91%
Mar	69	73	95%	87% to 98%
Apr	140	144	97%	93% to 99%
May	125	126	99%	96% to 100%
Jun	135	138	98%	94% to 99%
Jul	112	114	98%	94% to 100%
Aug	82	86	95%	89% to 98%
Sep	67	74	91%	82% to 95%
Oct	48	51	94%	84% to 98%
Nov	39	43	91%	78% to 96%
Dec	32	44	73%	58% to 84%

Peak flowering in May. Each bar is the share of Erigeron glaucus 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. 914 of 974 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 California found Erigeron glaucus 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

Erigeron glaucus

seaside daisy

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.