When does coyote gourd bloom in California?

Most often in July. Across 267 dated, research-grade observations of Cucurbita palmata in California, the flowering season runs roughly April to October.

Peak July In flower 267 Examined 1,157 State California

Flowering 267 in flower of 1,157 examined

34%

39%

36%

41%

32%

36%

38%

14%

Proportion of examined Cucurbita palmata in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	73	1%	0% to 7%
Feb	0	69	0%	0% to 5%
Mar	9	105	9%	5% to 15%
Apr	42	123	34%	26% to 43%
May	38	97	39%	30% to 49%
Jun	23	64	36%	25% to 48%
Jul	20	49	41%	28% to 55%
Aug	14	44	32%	20% to 47%
Sep	29	81	36%	26% to 47%
Oct	66	174	38%	31% to 45%
Nov	22	158	14%	9% to 20%
Dec	3	120	3%	1% to 7%

Peak flowering in Jul. Each bar is the share of Cucurbita palmata 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. 267 of 1,157 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 Cucurbita palmata 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

Cucurbita palmata

coyote gourd

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.