When does hairy ruellia bloom in Texas?

Most often in August. Across 260 dated, research-grade observations of Ruellia humilis in Texas, the flowering season runs roughly May to October.

Peak August In flower 260 Examined 305 State Texas

Flowering 260 in flower of 305 examined

14%

62%

81%

98%

93%

100%

98%

87%

Proportion of examined Ruellia humilis in Texas in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	1	too few examined
Mar	1	7	14%	3% to 51%
Apr	34	55	62%	49% to 73%
May	25	31	81%	64% to 91%
Jun	46	47	98%	89% to 100%
Jul	50	54	93%	82% to 97%
Aug	40	40	100%	91% to 100%
Sep	50	51	98%	90% to 100%
Oct	13	15	87%	62% to 96%
Nov	1	4	too few examined
Dec	0	0	too few examined

Peak flowering in Aug. Each bar is the share of Ruellia humilis in Texas 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. 260 of 305 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 months have fewer than 5 examined observations, so no proportion is drawn for them. 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 Texas found Ruellia humilis in flower, not a forecast. It is computed only from observations made in Texas, 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

Ruellia humilis

hairy ruellia

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Texas. 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.