When does California dodder bloom in California?

Most often in September. Across 161 dated, research-grade observations of Cuscuta californica in California, the flowering season runs roughly July to December.

Peak September In flower 161 Examined 262 State California

Flowering 161 in flower of 262 examined

36%

58%

36%

33%

60%

72%

78%

85%

92%

80%

63%

81%

Proportion of examined Cuscuta californica in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	4	11	36%	15% to 65%
Feb	15	26	58%	39% to 74%
Mar	17	47	36%	24% to 50%
Apr	9	27	33%	19% to 52%
May	12	20	60%	39% to 78%
Jun	21	29	72%	54% to 85%
Jul	18	23	78%	58% to 90%
Aug	23	27	85%	68% to 94%
Sep	12	13	92%	67% to 99%
Oct	12	15	80%	55% to 93%
Nov	5	8	63%	31% to 86%
Dec	13	16	81%	57% to 93%

Peak flowering in Sep. Each bar is the share of Cuscuta 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. 161 of 262 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 Cuscuta 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

Cuscuta californica

California dodder

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.