When does Pacific pea bloom in California?

Most often in March. Across 1,330 dated, research-grade observations of Lathyrus vestitus in California, the flowering season runs roughly January to December.

Peak March In flower 1,330 Examined 1,413 State California

Flowering 1,330 in flower of 1,413 examined

96%

95%

97%

96%

97%

86%

63%

13%

50%

88%

81%

Proportion of examined Lathyrus vestitus in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	46	48	96%	86% to 99%
Feb	156	165	95%	90% to 97%
Mar	372	382	97%	95% to 99%
Apr	412	430	96%	93% to 97%
May	231	239	97%	94% to 98%
Jun	76	88	86%	78% to 92%
Jul	12	19	63%	41% to 81%
Aug	0	2	too few examined
Sep	1	8	13%	2% to 47%
Oct	4	8	50%	22% to 78%
Nov	7	8	88%	53% to 98%
Dec	13	16	81%	57% to 93%

Peak flowering in Mar. Each bar is the share of Lathyrus vestitus 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. 1,330 of 1,413 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. 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 Lathyrus vestitus 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

Lathyrus vestitus

Pacific pea

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.