When does common chickweed bloom in Washington?

Most often in February. Across 134 dated, research-grade observations of Stellaria media in Washington, the flowering season runs roughly January to December.

Peak February In flower 134 Examined 146 State Washington

Flowering 134 in flower of 146 examined

Proportion of examined Stellaria media in Washington in flower, by month
Month In flower Examined Share 95% interval
Jan 16 20 80% 58% to 92%
Feb 20 20 100% 84% to 100%
Mar 30 30 100% 89% to 100%
Apr 36 37 97% 86% to 100%
May 3 3 too few examined
Jun 2 2 too few examined
Jul 0 0 too few examined
Aug 1 1 too few examined
Sep 3 7 43% 16% to 75%
Oct 3 3 too few examined
Nov 6 7 86% 49% to 97%
Dec 14 16 88% 64% to 97%

Peak flowering in Feb. Each bar is the share of Stellaria media in Washington 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. 134 of 146 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 Washington found Stellaria media in flower, not a forecast. It is computed only from observations made in Washington, 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 Washington. 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.