When does Bisbee Peak rushrose bloom in California?

Most often in February. Across 419 dated, research-grade observations of Crocanthemum scoparium in California, the flowering season runs roughly January to December.

Peak February In flower 419 Examined 433 State California

Flowering 419 in flower of 433 examined

Proportion of examined Crocanthemum scoparium in California in flower, by month
Month In flower Examined Share 95% interval
Jan 18 21 86% 65% to 95%
Feb 25 25 100% 87% to 100%
Mar 45 46 98% 89% to 100%
Apr 85 88 97% 90% to 99%
May 117 118 99% 95% to 100%
Jun 47 48 98% 89% to 100%
Jul 18 19 95% 75% to 99%
Aug 16 16 100% 81% to 100%
Sep 9 10 90% 60% to 98%
Oct 19 21 90% 71% to 97%
Nov 10 10 100% 72% to 100%
Dec 10 11 91% 62% to 98%

Peak flowering in Feb. Each bar is the share of Crocanthemum scoparium 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. 419 of 433 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 Crocanthemum scoparium 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

Sourcesevery claim on this page

  1. 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.
  2. World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.