When does paleface bloom in Arizona?

Most often in May. Across 201 dated, research-grade observations of Hibiscus denudatus in Arizona, the flowering season runs roughly February to November.

Peak May In flower 201 Examined 225 State Arizona

Flowering 201 in flower of 225 examined

72%

86%

98%

95%

100%

95%

100%

83%

93%

86%

61%

Proportion of examined Hibiscus denudatus in Arizona in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	13	18	72%	49% to 88%
Feb	19	22	86%	67% to 95%
Mar	50	51	98%	90% to 100%
Apr	36	38	95%	83% to 99%
May	7	7	100%	65% to 100%
Jun	0	0	too few examined
Jul	18	19	95%	75% to 99%
Aug	11	11	100%	74% to 100%
Sep	10	12	83%	55% to 95%
Oct	14	15	93%	70% to 99%
Nov	12	14	86%	60% to 96%
Dec	11	18	61%	39% to 80%

Peak flowering in May. Each bar is the share of Hibiscus denudatus in Arizona 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. 201 of 225 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. 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 Arizona found Hibiscus denudatus in flower, not a forecast. It is computed only from observations made in Arizona, 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 denudatus

paleface

Sourcesevery claim on this page

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