When does alkali heliotrope bloom in California?

Most often in June. Across 1,283 dated, research-grade observations of Heliotropium curassavicum in California, the flowering season runs roughly March to November.

Peak June In flower 1,283 Examined 1,333 State California

Flowering 1,283 in flower of 1,333 examined

57%

76%

96%

95%

99%

100%

99%

98%

95%

83%

71%

Proportion of examined Heliotropium curassavicum in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	8	14	57%	33% to 79%
Feb	13	17	76%	53% to 90%
Mar	48	50	96%	87% to 99%
Apr	117	123	95%	90% to 98%
May	145	147	99%	95% to 100%
Jun	204	205	100%	97% to 100%
Jul	216	218	99%	97% to 100%
Aug	182	184	99%	96% to 100%
Sep	190	193	98%	96% to 99%
Oct	93	98	95%	89% to 98%
Nov	50	60	83%	72% to 91%
Dec	17	24	71%	51% to 85%

Peak flowering in Jun. Each bar is the share of Heliotropium curassavicum 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. 1,283 of 1,333 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 Heliotropium curassavicum 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

Heliotropium curassavicum

alkali heliotrope

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.