When does greenspot nightshade bloom in California?

Most often in November. Across 635 dated, research-grade observations of Solanum douglasii in California, the flowering season runs roughly January to December.

Peak November In flower 635 Examined 663 State California

Flowering 635 in flower of 663 examined

96%

97%

99%

97%

99%

96%

78%

89%

97%

93%

100%

97%

Proportion of examined Solanum douglasii in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	51	53	96%	87% to 99%
Feb	64	66	97%	90% to 99%
Mar	87	88	99%	94% to 100%
Apr	91	94	97%	91% to 99%
May	73	74	99%	93% to 100%
Jun	45	47	96%	86% to 99%
Jul	29	37	78%	63% to 89%
Aug	33	37	89%	75% to 96%
Sep	30	31	97%	84% to 99%
Oct	42	45	93%	82% to 98%
Nov	52	52	100%	93% to 100%
Dec	38	39	97%	87% to 100%

Peak flowering in Nov. Each bar is the share of Solanum douglasii 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. 635 of 663 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 Solanum douglasii 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

Solanum douglasii

greenspot nightshade

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.