When does Alkali Goldenbush bloom in California?

Most often in November. Across 445 dated, research-grade observations of Isocoma acradenia in California, the flowering season runs roughly October to November.

Peak November In flower 445 Examined 883 State California

Flowering 445 in flower of 883 examined

26%

13%

75%

62%

90%

95%

70%

Proportion of examined Isocoma acradenia in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	25	95	26%	19% to 36%
Feb	1	112	1%	0% to 5%
Mar	1	86	1%	0% to 6%
Apr	0	65	0%	0% to 6%
May	3	23	13%	5% to 32%
Jun	0	7	0%	0% to 35%
Jul	6	8	75%	41% to 93%
Aug	2	4	too few examined
Sep	23	37	62%	46% to 76%
Oct	106	118	90%	83% to 94%
Nov	181	190	95%	91% to 97%
Dec	97	138	70%	62% to 77%

Peak flowering in Nov. Each bar is the share of Isocoma acradenia 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. 445 of 883 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 California found Isocoma acradenia 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

Isocoma acradenia

Alkali Goldenbush

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.