When does Common Sunflower bloom in Texas?

Most often in February. Across 924 dated, research-grade observations of Helianthus annuus in Texas, the flowering season runs roughly January to December.

Peak February In flower 924 Examined 987 State Texas

Flowering 924 in flower of 987 examined

Proportion of examined Helianthus annuus in Texas in flower, by month
Month In flower Examined Share 95% interval
Jan 11 12 92% 65% to 99%
Feb 9 9 100% 70% to 100%
Mar 27 30 90% 74% to 97%
Apr 122 150 81% 74% to 87%
May 100 118 85% 77% to 90%
Jun 151 157 96% 92% to 98%
Jul 141 143 99% 95% to 100%
Aug 111 112 99% 95% to 100%
Sep 107 108 99% 95% to 100%
Oct 97 98 99% 94% to 100%
Nov 31 33 94% 80% to 98%
Dec 17 17 100% 82% to 100%

Peak flowering in Feb. Each bar is the share of Helianthus annuus 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. 924 of 987 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 Helianthus annuus 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

Sourcesevery claim on this page

  1. 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.
  2. World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.