When does Field madder bloom in Tennessee?

Most often in April. Across 262 dated, research-grade observations of Sherardia arvensis in Tennessee, the flowering season runs roughly April to June.

Peak April In flower 262 Examined 287 State Tennessee

Flowering 262 in flower of 287 examined

Proportion of examined Sherardia arvensis in Tennessee in flower, by month
Month In flower Examined Share 95% interval
Jan 2 3 too few examined
Feb 2 10 20% 6% to 51%
Mar 55 71 77% 66% to 86%
Apr 87 87 100% 96% to 100%
May 70 70 100% 95% to 100%
Jun 33 33 100% 90% to 100%
Jul 2 2 too few examined
Aug 2 2 too few examined
Sep 1 1 too few examined
Oct 4 4 too few examined
Nov 2 2 too few examined
Dec 2 2 too few examined

Peak flowering in Apr. Each bar is the share of Sherardia arvensis in Tennessee 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. 262 of 287 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 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 Tennessee found Sherardia arvensis in flower, not a forecast. It is computed only from observations made in Tennessee, 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 Tennessee. 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.