Spotted Knapweed (Centaurea stoebe) is in the Sunflowers, Daisies, Asters, and Allies family (Asteraceae). Across the U.S., iNaturalist users have logged 2,339 research-grade flowering observations of it in our sample, peaking in July.
Nationally it blooms mainly from July to September, but timing varies a lot by state and elevation — see the table below.
When to photograph Spotted Knapweed: observations by month (U.S.)
About Spotted Knapweed
Centaurea stoebe is a species of Centaurea found in Northern Italy. It is also an invasive species in the United States, and particularly widespread in dryer regions of the Pacific Northwest. This species along with Centaurea diffusa are the stereotypical "tumbleweed" of the West- breaking off at the top of the roots which facilitates its seeds spreading far and wide, but arean't actually native to the North American continent, but to a similar dry climate in...From Wikipedia via iNaturalist — article, CC BY-SA.
Spotted Knapweed by state
| State | Observations | Peak month | Main season |
|---|---|---|---|
| Minnesota | 224 | July | Jul–Sep |
| Massachusetts | 219 | July | Jul–Sep |
| Vermont | 216 | July | Jul–Aug |
| New York | 213 | July | Jul–Oct |
| Wisconsin | 198 | July | Jul–Sep |
| Michigan | 169 | July | Jul–Sep |
| Virginia | 148 | July | Jun–Sep |
| Pennsylvania | 138 | July | Jul–Sep |
| Washington | 102 | August | Jul–Sep |
| New Jersey | 100 | July | Jun–Oct |
| Montana | 87 | July | Jul–Oct |
| Oregon | 64 | August | Jul–Oct |
| Maryland | 62 | July | Jul–Aug |
| Idaho | 47 | October | Jul–Oct |
| Wyoming | 46 | August | Jul–Sep |
| North Carolina | 39 | July | Jul–Oct |
| Arkansas | 38 | July | Jun–Aug |
| Missouri | 28 | July | Jun–Aug |
| Colorado | 27 | August | Jul–Oct |
| Connecticut | 26 | July | Jul–Aug |
| New Hampshire | 26 | July | Jul–Aug |
| Utah | 19 | September | Jul–Oct |
| West Virginia | 17 | July | Jun–Jul |
| Illinois | 15 | July | Jul–Jul |
| District of Columbia | 13 | June | Jun–Aug |
| Arizona | 11 | July | Jul–Jul |
| Rhode Island | 10 | July | Jun–Oct |
| Delaware | 8 | August | Jul–Aug |
| Ohio | 6 | July | Jul–Aug |
| Maine | 5 | July | Jul–Jul |
Main season = months with at least 30% of the state's peak-month count.
Related wildflowers (Sunflowers, Daisies, Asters, and Allies)
black-eyed Susan
Common Yarrow
White Snakeroot
Chicory
Lawn daisy
Philadelphia fleabane
Pearly Everlasting
Blue Mistflower
Photography tips
- Photograph flowers on calm, overcast mornings to avoid wind blur and harsh shadows.
- Get low: a shallow depth of field (f/2.8–f/5.6) isolates a bloom against soft color.
- Stay on trails — trampling meadows kills plants and ruins next year's display.
- Try a kaleidoscope abstract of a single bloom with our online kaleidoscope tool.
FAQ
When is the best time to photograph Spotted Knapweed?
Nationally, July has the most observations, with the main season from July to September.
Where is Spotted Knapweed most often seen?
The most observations come from Minnesota, Massachusetts, Vermont.