When does California Wild Rose bloom in California?

Most often in June. Across 2,040 dated, research-grade observations of Rosa californica in California, the flowering season runs roughly May to July.

Peak June In flower 2,040 Examined 2,933 State California

Flowering 2,040 in flower of 2,933 examined

35%

31%

48%

74%

93%

83%

59%

41%

31%

36%

31%

Proportion of examined Rosa californica in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	17	49	35%	23% to 49%
Feb	16	51	31%	20% to 45%
Mar	19	40	48%	33% to 63%
Apr	148	199	74%	68% to 80%
May	511	550	93%	90% to 95%
Jun	559	601	93%	91% to 95%
Jul	321	385	83%	79% to 87%
Aug	171	288	59%	54% to 65%
Sep	125	305	41%	36% to 47%
Oct	69	221	31%	25% to 38%
Nov	57	158	36%	29% to 44%
Dec	27	86	31%	23% to 42%

Peak flowering in Jun. Each bar is the share of Rosa californica 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. 2,040 of 2,933 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 Rosa californica 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

Rosa californica

California Wild Rose

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.