Bloom Reports from the Anza-Borrego Desert: 2023-2024

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

Fig. 1. Left: Langloisia setosissima, bristly Langloisia. Note how tiny this plant is, with only a single flower, instead of the usual mound of flowers for this species. Right: Opuntia basilaris, beavertail cactus. Both photographs taken on 1 April 2024 in the vicinity of the lower part of S22 just above the Hellhole Canyon parking area / Little Surprise Canyon, by Tom Chester.

Click on the pix to go to the iNat obs of each, showing exactly where those photos were taken.

Latest Summary of Bloom Status

Summary as of 5 April 2024

This is the last update of this page for this bloom year.

Peak bloom on the desert floor, at 200 to ~1000 feet elevation, occurred in mid-March 2024, and ended rapidly in the last two weeks of March. Although there are still many annual plants in bloom in many places, most annual plants have finished blooming, and many are already crisped. The average desert floor high temperature is now 85 degrees, and with the predicted high temps of ~90 degrees next week, most of the annuals should be crisped up soon.

As usual, now that the desert annual show is past peak, cacti have begun to bloom, with abundant showy blooms from beavertail cactus.

This year, like all the recent years, was unusual. It was the best bloom for desert lilies in recent memory, with thousands of desert lilies in bloom in many places, a bloom that continued for about a month, with each plant producing flower after flower. The vast majority of those plants have finished blooming now.

The good annual displays in the sandy areas, of desert hairy sunflower and sand verbena, finished not because it got hot, but because they ran out of water stored in the sand. It was shocking how quickly the bloom ended. Sand verbena transitioned in just a week or two from plants in full bloom, to plants looking nearly dead. Compare pix from 27 March 2024 to a pix of the same plants taken just four days earlier!

In normal years, peak bloom progresses to successively-higher elevations. But so far we haven't seen any examples of what would normally be "peak bloom" at higher elevations that include annuals. It has been so cold at higher elevations for months that annual plants couldn't grow as much as normal. Many of the annual blooms at higher elevations are on very small plants. Ted Caragozian hiked the California Riding and Hiking Trail from Culp Valley to Hellhole Canyon, and didn't find anyplace that he would have described as being in peak bloom, except for the beavertail cactus in its lower part.

Perennials and shrubs should have a very good bloom at higher elevations when it finally warms up, since higher elevations got a lot of rain this year. Brittlebush, Encelia farinosa, is finally putting on a decent display along S22 in Montezuma Grade where it descends to the desert floor.

In the end, the desert floor only got roughly normal precipitation for January through March, 2 to 3 inches, which is the same as the median to average rainfall for those months. In contrast, areas west of the desert floor got increasingly higher percentages of above-normal rainfall, with the mountain crest getting roughly twice its normal rainfall for January through March.

You can explore the state of the bloom yourself from the comfort of home with the iNat 2,152 observations of 292 species posted at iNat since 29 March 2024 (numbers are as of 5 April 2024; your numbers will be more as more obs are added from later dates). Click on "Filters" in the upper right to change the date range if you want to see only very recent observations.

Note that some of the species in bloom with only a few observations may be represented by only a single individual, or a small number of individuals. Also, how many and which species you see in bloom on your hike is largely determined by where you hike and how far you hike. Many species are restricted to a certain elevation range, or certain locations.

Click on the "Map" tab at the link and you can zoom into the map to see where the reports are. Once you zoom into a given area, click on the "Redo search in map", or use the rectangular or circular area tool to circumscribe your area, to find out how many flower observations there are in your desired area. Each observation gives the date and time of observation, and the latitude and longitude for each observation, which is plotted on a map so you can see where it was observed (rare species have obscured coordinates, which have a different symbol on the map and wildly-inaccurate coordinates from the obscuration).

See also previous versions of this page.

Background information on this year's bloom.

This is the third year in a row with good monsoonal rain in the Borrego Desert, which makes this yet another year in which the desert blooms consist of two very different components.

The first component is from plants that responded to monsoonal rains, specifically the unusually-good rain from the remnants of Tropical Storm Hilary on 19-20 August 2023. Hilary dumped seven inches on both Ranchita and Mt. Laguna, and the desert floor received a widespread two inches.

That rain resulted in widespread appearance of monsoonal species on the desert floor, especially Pectis papposa, chinchweed; Kallstroemia californica, California caltrop; Palafoxia arida, Spanish needles; and Allionia incarnata, trailing four o'clock. Those plants were probably in full bloom from mid-September through mid-October, but their bloom quickly declined after that, which is usually the case. Last year, their bloom hung on much later, since the rain that year came a month later.

As of 10 January 2024, the Kallstroemia plants were essentially all finished fruiting and dead, as were most of the Pectis and Palafoxia plants except for scattered individuals. Most Allionia plants on the desert floor were dead and finished, but increasing numbers of them are still alive as one heads into the hills west of Borrego Springs.

That August rain also germinated a very small number, in most places, of our usual spring plants in the sandiest areas of the desert, such as Abronia villosa, desert sand verbena; Perityle emoryi, Emory's rock daisy; and Geraea canescens, desert sunflower. There are many fewer plants of those species this year than came from the September rain in the previous summer. For example, last year there were spectacular carpets of sand verbena from October through March. This year, there are only isolated plants of those species in most areas. Those plants began blooming in October, and are still going strong as of 4 March 2024. See a map of those species, plus Palafoxia, observed since 1 December 2023, showing where those sandy areas are.

The second component comes from the usual late winter / early spring bloomers. There was a good bloom from them, albeit mostly on smaller-than-normal plants.

A few tenths of an inch of rain fell on 13-14 November 2023, and a half to 3/4 of an inch fell on 21-22 December 2024, with both rains widespread on the desert floor. The desert received another widespread 1.0 to 1.5 inches of rain on 21-22 January 2024, which was enough to produce widespread germination. Another widespread 0.5 to 0.9 inches fell on 4-9 February 2024, and another few tenths on 19-21 February 2024.

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.

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


For many more bloom reports, see Anza-Borrego Wildflowers Bloom Report by Fred Melgert and Carla Hoegen.

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 20 December 2023 (click on "Filters" to change the dates; there were 1,984 observations of 272 species posted at iNat as of 12 January 2024)

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)

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Copyright © 2008-2024 by Tom Chester, Carla Hoegen, Fred Melgert, Don Rideout, and Jim Roberts.
Commercial rights reserved. Permission is granted to reproduce any or all of this page for individual or non-profit institutional internal use as long as credit is given to us at this source:
Comments and feedback: Tom Chester
Updated 5 April 2024