When does colt's-foot bloom in Pennsylvania?

Most often in March. Across 304 dated, research-grade observations of Tussilago farfara in Pennsylvania, the flowering season runs roughly March to April.

Peak March In flower 304 Examined 431 State Pennsylvania

Flowering 304 in flower of 431 examined

Proportion of examined Tussilago farfara in Pennsylvania in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 1 2 too few examined
Mar 138 152 91% 85% to 94%
Apr 151 189 80% 74% to 85%
May 13 36 36% 22% to 52%
Jun 0 6 0% 0% to 39%
Jul 0 4 too few examined
Aug 1 9 11% 2% to 44%
Sep 0 12 0% 0% to 24%
Oct 0 17 0% 0% to 18%
Nov 0 4 too few examined
Dec 0 0 too few examined

Peak flowering in Mar. Each bar is the share of Tussilago farfara in Pennsylvania 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. 304 of 431 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 5 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 Pennsylvania found Tussilago farfara in flower, not a forecast. It is computed only from observations made in Pennsylvania, 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 Pennsylvania. 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.