When does purple crownvetch bloom in New York?

Most often in July. Across 366 dated, research-grade observations of Coronilla varia in New York, the flowering season runs roughly June to October.

Peak July In flower 366 Examined 436 State New York

Flowering 366 in flower of 436 examined

Proportion of examined Coronilla varia in New York in flower, by month
Month In flower Examined Share 95% interval
Jan 0 4 too few examined
Feb 0 2 too few examined
Mar 0 0 too few examined
Apr 0 13 0% 0% to 23%
May 15 33 45% 30% to 62%
Jun 194 211 92% 87% to 95%
Jul 81 85 95% 89% to 98%
Aug 28 34 82% 66% to 92%
Sep 23 26 88% 71% to 96%
Oct 21 23 91% 73% to 98%
Nov 3 4 too few examined
Dec 1 1 too few examined

Peak flowering in Jul. Each bar is the share of Coronilla varia in New York 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. 366 of 436 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 New York found Coronilla varia in flower, not a forecast. It is computed only from observations made in New York, 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 New York. 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.