When does California Barrel Cactus bloom in California?

Most often in April. Across 1,956 dated, research-grade observations of Ferocactus acanthodes in California, the flowering season runs roughly March to April.

Peak April In flower 1,956 Examined 5,555 State California

Flowering 1,956 in flower of 5,555 examined

26%

57%

65%

34%

12%

13%

Proportion of examined Ferocactus acanthodes in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	16	551	3%	2% to 5%
Feb	220	854	26%	23% to 29%
Mar	833	1464	57%	54% to 59%
Apr	688	1057	65%	62% to 68%
May	108	315	34%	29% to 40%
Jun	7	60	12%	6% to 22%
Jul	2	47	4%	1% to 14%
Aug	2	57	4%	1% to 12%
Sep	15	113	13%	8% to 21%
Oct	8	283	3%	1% to 5%
Nov	25	327	8%	5% to 11%
Dec	32	427	7%	5% to 10%

Peak flowering in Apr. Each bar is the share of Ferocactus acanthodes 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. 1,956 of 5,555 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 Ferocactus acanthodes 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

Ferocactus acanthodes

California Barrel Cactus

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.