When does Heartleaf Hibiscus bloom in Texas?

Most often in June. Across 269 dated, research-grade observations of Hibiscus martianus in Texas, the flowering season runs roughly March to October.

Peak June In flower 269 Examined 362 State Texas

Flowering 269 in flower of 362 examined

54%

76%

89%

71%

73%

100%

90%

83%

92%

82%

61%

39%

Proportion of examined Hibiscus martianus in Texas in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	7	13	54%	29% to 77%
Feb	13	17	76%	53% to 90%
Mar	31	35	89%	74% to 95%
Apr	51	72	71%	59% to 80%
May	27	37	73%	57% to 85%
Jun	20	20	100%	84% to 100%
Jul	18	20	90%	70% to 97%
Aug	10	12	83%	55% to 95%
Sep	24	26	92%	76% to 98%
Oct	31	38	82%	67% to 91%
Nov	25	41	61%	46% to 74%
Dec	12	31	39%	24% to 56%

Peak flowering in Jun. Each bar is the share of Hibiscus martianus 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. 269 of 362 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 Texas found Hibiscus martianus 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

Hibiscus martianus

Heartleaf Hibiscus

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.