When does common water hyacinth bloom in Florida?

Most often in October. Across 175 dated, research-grade observations of Pontederia crassipes in Florida, the flowering season runs roughly April to November.

Peak October In flower 175 Examined 226 State Florida

Flowering 175 in flower of 226 examined

17%

18%

80%

90%

81%

90%

94%

77%

97%

81%

68%

Proportion of examined Pontederia crassipes in Florida in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	6	17%	3% to 56%
Feb	0	7	0%	0% to 35%
Mar	2	11	18%	5% to 48%
Apr	12	15	80%	55% to 93%
May	26	29	90%	74% to 96%
Jun	13	16	81%	57% to 93%
Jul	18	20	90%	70% to 97%
Aug	17	18	94%	74% to 99%
Sep	20	26	77%	58% to 89%
Oct	31	32	97%	84% to 99%
Nov	22	27	81%	63% to 92%
Dec	13	19	68%	46% to 85%

Peak flowering in Oct. Each bar is the share of Pontederia crassipes in Florida 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. 175 of 226 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 Florida found Pontederia crassipes in flower, not a forecast. It is computed only from observations made in Florida, 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

Pontederia crassipes

common water hyacinth

Sourcesevery claim on this page

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