Bloom Reports from the Anza-Borrego Desert: 2025-2026
Table of Contents
Latest Summary of Bloom Status
Bloom Reports from Individual Hikes This Season
Links to Other Webpages on Anza-Borrego Desert State Park Blooms
Background Information for Bloom Reports from the Anza-Borrego Desert
Older Bloom Reports from 2009 to present
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| Fig. 1. Top Left: Mammillaria tetrancistra (=Cochemiea t.), common fishhook cactus, photographed by Jim Roberts on 1 September 2025 in the Agua Caliente County Park area.
Top Right: A fully leafed-out ocotillo, Fouqieria splendens, photographed by Tom Chester on 1 September 2025 in the Agua Caliente County Park area. Bottom: Good monsoonal annual germination on Split Mountain Road, about a mile south of SR78, photographed by Tom Chester on 10 September 2025. Click on the pix to go to the iNat obs of each. | |
Latest Summary of Bloom Status
Summary as of 11 September 2025
Monsoonal plants are just about to burst into bloom generally! The first devil's claws, Proboscidea althifolia, have begun bloom; see this gorgeous plant posted by @ramonamom on 10 or 11 September 2025. On 10 September 2025, We observed four monsoonal annual species that will begin blooming in just a day or two: chinchweed, Pectis papposa; Kallstroemia californica; five wing spiderling, Boerhavia triquetra intermedia; and fringed amaranth, Amaranthus fimbriatus.
The best place to observe large numbers of monsoonal annuals is Split Mountain Road, south of Ocotillo Wells.
But watch out for the no-see-ums! Unfortunately, when the monsoonal annuals start blooming, the biting flies appear with them. Take a head-net if you go out.
The rainfall part of the monsoon season finally began on 25 August 2025, when fairly widespread rain greened up our ocotillos. However, annual germination is confined to two main areas so far:
- the area along highway S2 over a stretch of about ten miles, from Campbell Grade / Vallecito Valley to just north of Indian / Torote Canyons. There is only scattered germination along that stretch of road. See our Botanical Report from 1 September 2010 of that area, and the 89 obs of 24 species posted from that trip.
- the area along Split Mountain Road between Ocotillo Wells and the Fish Creek Mountains. There are massive number of annuals along two stretches of that Road. See our Botanical Report from 10 September 2010 of that area, as well as other ares where we did not observe germination. See our 39 obs of 26 species posted from that trip.
See Monsoonal Species for a list of the species that respond significantly to monsoonal rainfall.
Monsoonal annuals grow quickly, and normally would be expected to begin blooming four to six weeks after the rainfall, which would be the last part of September and the first part of October 2025.
However, the very first bloomer, Mammillaria tetrancistra (=Cochemiea t.), common fishhook cactus, is finished blooming now. It might rebloom 5 to 7 days after future monsoonal rain, if we get any more in the last half of September.
Additional monsoonal rain has fallen since 25 August 2025, including almost an inch in the Borrego Springs area, measured in a gauge near the Roadrunner Mobile Park. More rain may have fallen in the area east of there where there are no rain gauges.
See also previous versions of this page.
Bloom Reports from Individual Hikes This Season
The latest bloom reports are given first (i.e., the reports are in inverse order of time). As detailed immediately above, you can see a map of where the hikes were from any linked iNat post of the species in bloom.
10 September 2025: car trip from Borrego Springs to Salton City, and back via SR78.
1 September 2025: car trip from the San Felipe Valley to Indian Gorge / Torote Canyon.
For many more bloom reports, see Anza-Borrego Wildflowers Bloom Report by Fred Melgert and Carla Hoegen.
Bloom Reports not yet added to this page
Links to Other Webpages on Anza-Borrego Desert State Park Blooms
Anza-Borrego Wildflowers Bloom Report by Fred Melgert and Carla Hoegen, often with daily wildflower updates.
All iNaturalist observations in the Borrego Desert since 15 August 2025, 281 observations of 82 species (numbers are as of 12 September 2025; click on "Filters" to change the dates).
Wildflower Updates from the Anza-Borrego Desert Natural History Association.
Anza-Borrego Desert State Park official site, with wildflower information on it. When they start producing current wildflower reports, click on the link near the top with the word Update, which might be updated weekly.
DesertUSA Anza-Borrego Desert State Park Wildflower Reports
Anza-Borrego Foundation and Institute Wildflowers and their Anza-Borrego Desert State Park Wildflower Hotline: (760)767-4684. "Information on this recording is updated regularly."
Theodore Payne Wildflower Hotline (Reports begin the first Friday in March)