When does sugar bush bloom in California?

Most often in April. Across 230 dated, research-grade observations of Rhus ovata in California, the flowering season runs roughly April.

Peak April In flower 230 Examined 882 State California

Flowering 230 in flower of 882 examined

12%

10%

38%

61%

27%

13%

14%

Proportion of examined Rhus ovata in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	13	110	12%	7% to 19%
Feb	10	100	10%	6% to 17%
Mar	70	184	38%	31% to 45%
Apr	100	164	61%	53% to 68%
May	15	55	27%	17% to 40%
Jun	4	31	13%	5% to 29%
Jul	1	16	6%	1% to 28%
Aug	0	20	0%	0% to 16%
Sep	1	23	4%	1% to 21%
Oct	2	53	4%	1% to 13%
Nov	3	47	6%	2% to 17%
Dec	11	79	14%	8% to 23%

Peak flowering in Apr. Each bar is the share of Rhus ovata 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. 230 of 882 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 Rhus ovata 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

Rhus ovata

sugar bush

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.