When does Funastrum heterophyllum bloom in California?

Most often in July. Across 361 dated, research-grade observations of Funastrum heterophyllum in California, the flowering season runs roughly April to September.

Peak July In flower 361 Examined 490 State California

Flowering 361 in flower of 490 examined

30%

53%

79%

92%

86%

80%

100%

82%

80%

73%

64%

32%

Proportion of examined Funastrum heterophyllum in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	7	23	30%	16% to 51%
Feb	18	34	53%	37% to 69%
Mar	64	81	79%	69% to 86%
Apr	80	87	92%	84% to 96%
May	50	58	86%	75% to 93%
Jun	20	25	80%	61% to 91%
Jul	16	16	100%	81% to 100%
Aug	9	11	82%	52% to 95%
Sep	24	30	80%	63% to 91%
Oct	38	52	73%	60% to 83%
Nov	23	36	64%	48% to 78%
Dec	12	37	32%	20% to 49%

Peak flowering in Jul. Each bar is the share of Funastrum heterophyllum 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. 361 of 490 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 Funastrum heterophyllum 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

Funastrum heterophyllum

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.