When does chamise bloom in California?

Most often in June. Across 1,875 dated, research-grade observations of Adenostoma fasciculatum in California, the flowering season runs roughly May to July.

Peak June In flower 1,875 Examined 3,055 State California

Flowering 1,875 in flower of 3,055 examined

18%

42%

47%

81%

96%

79%

52%

21%

11%

13%

Proportion of examined Adenostoma fasciculatum in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	3	82	4%	1% to 10%
Feb	18	102	18%	11% to 26%
Mar	82	196	42%	35% to 49%
Apr	250	533	47%	43% to 51%
May	708	869	81%	79% to 84%
Jun	531	556	96%	93% to 97%
Jul	182	229	79%	74% to 84%
Aug	53	101	52%	43% to 62%
Sep	24	117	21%	14% to 29%
Oct	9	81	11%	6% to 20%
Nov	12	89	13%	8% to 22%
Dec	3	100	3%	1% to 8%

Peak flowering in Jun. Each bar is the share of Adenostoma fasciculatum 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. 1,875 of 3,055 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 Adenostoma fasciculatum 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

Adenostoma fasciculatum

chamise

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.