When does white clover bloom in Pennsylvania?

Most often in June. Across 316 dated, research-grade observations of Trifolium repens in Pennsylvania, the flowering season runs roughly May to November.

Peak June In flower 316 Examined 376 State Pennsylvania

Flowering 316 in flower of 376 examined

Proportion of examined Trifolium repens in Pennsylvania in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 0 0 too few examined
Mar 0 8 0% 0% to 32%
Apr 9 24 38% 21% to 57%
May 97 110 88% 81% to 93%
Jun 82 84 98% 92% to 99%
Jul 32 36 89% 75% to 96%
Aug 17 20 85% 64% to 95%
Sep 49 52 94% 84% to 98%
Oct 23 33 70% 53% to 83%
Nov 7 8 88% 53% to 98%
Dec 0 1 too few examined

Peak flowering in Jun. Each bar is the share of Trifolium repens 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. 316 of 376 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 3 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 Trifolium repens 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.