When does staghorn sumac bloom in Maine?

Most often in June. Across 53 dated, research-grade observations of Rhus typhina in Maine, the flowering season runs roughly June.

Peak June In flower 53 Examined 392 State Maine

Flowering 53 in flower of 392 examined

Proportion of examined Rhus typhina in Maine in flower, by month
Month In flower Examined Share 95% interval
Jan 0 7 0% 0% to 35%
Feb 0 14 0% 0% to 22%
Mar 0 8 0% 0% to 32%
Apr 0 12 0% 0% to 24%
May 1 11 9% 2% to 38%
Jun 16 41 39% 26% to 54%
Jul 31 104 30% 22% to 39%
Aug 5 106 5% 2% to 11%
Sep 0 40 0% 0% to 9%
Oct 0 32 0% 0% to 11%
Nov 0 9 0% 0% to 30%
Dec 0 8 0% 0% to 32%

Peak flowering in Jun. Each bar is the share of Rhus typhina in Maine 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. 53 of 392 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 Maine found Rhus typhina in flower, not a forecast. It is computed only from observations made in Maine, 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 Maine. 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.