When does tree tobacco bloom in California?

Most often in April. Across 2,069 dated, research-grade observations of Nicotiana glauca in California, the flowering season runs roughly March to December.

Peak April In flower 2,069 Examined 2,860 State California

Flowering 2,069 in flower of 2,860 examined

48%

64%

76%

81%

75%

71%

80%

78%

75%

78%

62%

66%

Proportion of examined Nicotiana glauca in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	90	189	48%	41% to 55%
Feb	140	219	64%	57% to 70%
Mar	266	348	76%	72% to 81%
Apr	346	426	81%	77% to 85%
May	186	248	75%	69% to 80%
Jun	161	227	71%	65% to 76%
Jul	184	231	80%	74% to 84%
Aug	164	209	78%	72% to 84%
Sep	114	153	75%	67% to 81%
Oct	141	181	78%	71% to 83%
Nov	123	197	62%	56% to 69%
Dec	154	232	66%	60% to 72%

Peak flowering in Apr. Each bar is the share of Nicotiana glauca 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. 2,069 of 2,860 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 Nicotiana glauca 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

Nicotiana glauca

tree tobacco

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.