When does rush milkweed bloom in Nevada?

Most often in October. Across 169 dated, research-grade observations of Asclepias subulata in Nevada, the flowering season runs roughly May to December.

Peak October In flower 169 Examined 266 State Nevada

Flowering 169 in flower of 266 examined

Proportion of examined Asclepias subulata in Nevada in flower, by month
Month In flower Examined Share 95% interval
Jan 4 10 40% 17% to 69%
Feb 0 6 0% 0% to 39%
Mar 2 37 5% 2% to 18%
Apr 31 53 58% 45% to 71%
May 44 49 90% 78% to 96%
Jun 13 14 93% 69% to 99%
Jul 4 5 80% 38% to 96%
Aug 2 8 25% 7% to 59%
Sep 6 10 60% 31% to 83%
Oct 14 15 93% 70% to 99%
Nov 19 25 76% 57% to 89%
Dec 30 34 88% 73% to 95%

Peak flowering in Oct. Each bar is the share of Asclepias subulata in Nevada 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. 169 of 266 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 Nevada found Asclepias subulata in flower, not a forecast. It is computed only from observations made in Nevada, 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 Nevada. 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.