Bloom Reports from the Anza-Borrego Desert: 2018-2019

Fig. 1. Proboscidea althaeifolia, desert unicorn-plant, devil's claw, in bloom and fruit at the parking area for Canyon 41, on 18 November 2018. Photo by Tom Chester. Click on the photo for a larger version.

Fig. 2. Hesperocallis undulata, desert lily, in full bloom in the San Felipe Creek area north of the Buttes Pass Road, on 7 December 2018. Photo by Tom Chester. Click on the photo for a larger version.


The Borrego Desert received widespread rain on 4 to 6 December 2018. Over an inch was recorded everyplace west of Borrego Springs, which is enough to germinate the annuals that will bloom in February and March, and even the desert floor east of Borrego Springs received over a half inch.

Although the vast majority of Anza-Borrego Desert State Park was dry as a bone as of 30 November 2018, a few favored areas received rain from thunderstorms on October 12 and 13, producing good annual germination, and have a number of plants already in bloom. There were well over 50 species of flowering plants in November in the Borrego Badlands and Canyon 41 / Canebrake areas! To the great surprise of many of us, we now have small numbers of desert lilies and cacti blooming in early December (see Ernie Cowan's San Diego Union Tribune column).

In those favored areas, the number of plants in bloom at this time of year is the best since 2013-2014, in the top three years out of the last decade for blooms in the late fall. See Number of Species and Plants in Bloom On Each Trip for a comparison of this year with previous years, and the summary table below.

In those favored areas, many plant species grew amazingly quickly from the heat and still-strong October / early November sun in the last month. Nearly all the ocotillos in those areas were wearing their coats of green leaves in mid-November, although some of the leaves were reaching their expiration date in late November.

Due primarily to four prolific observers, iNaturalist has become a wonderful resource to get almost daily updates on what is blooming in the Anza-Borrego Desert. Click on "Filters" and select a date range to see the observations from that period. For example, here are all the observations on 1 December 2018 and later. As of 9 December 2018, 834 observations were posted in those eight days, primarily contributed by Fred Melgert / Carla Hoegen, Don Rideout, Terry Hunefeld, and Birgit Knorr.

See also Background Information for Bloom Reports.

Canyon 41 / Canebrake area

It is easy to describe the favored area around Canyon 41 and Canebrake. As of late November, there was no germination at all along 41 miles of S2 from its northern end at mile marker zero (the junction with SR79) until mile marker 41, where there is an abrupt transition and the creosote plants are all blooming, the ocotillos are green, and there is good germination. In the Canyon 41 alluvial plain / Vallecito Creek / Ironwood Canyon area, Nancy Accola, Tom Chester, Carla Hoegen, Fred Melgert, Birgit Knorr, and Don Rideout found 55 species in bloom on 18 November 2018! South of Canebrake the good germination stops.

Borrego Badlands area

The situation in the Borrego Badlands area is more complicated, and is best shown with a map. Fig. 1 shows where baby annuals have been observed in the Borrego Badlands / Ocotillo Wells area, along with rainfall reports from stations in the Ocotillo Wells area, and areas where no germination was observed.

It is easy to find these locations using the green-clad ocotillos as flags. Along S22, the annuals are found from just east of Fonts Point Wash to Salton City. Along SR78, the annuals are found from just east of Borrego Springs Road to Ocotillo Wells. Fred and Carla have so far found the best germination in the San Felipe Wash area on the north side of the East Butte, close to the gauge that recorded 1.55" of rain, in washes that carried the runoff from the rainfall on the East Butte.

Fig. 1. Where the rain of October 13 produced annual germination in the Borrego Springs / Borrego Badlands Area. The Borrego Springs area west of this map is very dry, with no annual germination yet.

Interestingly, few plants of Erodium cicutarium have germinated, probably since it needs cooler temperatures to germinate.

Comparison of this year's Fall bloom to that of previous years

#pls#speciesseasonline color

The table is in declining order by # plants in bloom, where each species contributes a maximum of 99 plants. The current bloom is the third best in that category, and the second best in the average number of species in bloom.

The line color refers to the plots in Number of Species and Plants in Bloom On Each Trip.

Detailed observations for the Borrego Badlands Area

Fred and Carla drove S22 to the Salton Sea on 12 November 2018 and found roadside annuals all the way from the Thimble Trail to the Salton Sea, as well as signs of flooding in the washes near the Salton Sea.

The western black solid lines along S22 and SR78 in Fig. 1 are where Tom Chester, Kate Harper, and Don Rideout first saw leafed-out ocotillos and annual germination driving west of S22 and on SR78 on 14 November 2018. The "No annuals" label on the map east of the Ocotillo Wells County Airport is where they stopped seeing annuals driving east on SR78. The western black solid line along San Felipe Wash is where Fred and Carla observed a transition between some annuals to the east, and no annuals to the west.

Tom, Kate and Don stopped just east of Fonts Point Wash on 14 November 2018 to see who the annuals were. Along the immediate roadside, the annuals were unfortunately nearly 99% Brassica tournefortii. However, away from the roadside, Brassica tournefortii was only an estimated 10 to 20% of the annuals. This probably means that we will have one more good year in which natives are dominant in that area. However, this area may well become dominated by Brassica tournefortii in the near future if this year's baby mustard plants produce a large number of seeds, completing its comeback from its near total-wipeout by the drought of 2011 to 2014.

Fred and Carla report that as of last year, Brassica tournefortii had already re-taken the Borrego Dunes / Ant Hill between the County Dump Road and Fonts Point.

Fred and Carla did a car tour through the Borrego Badlands on 19 November 2018 specifically to check where germination had occurred, driving the Arroyo Salado, Ella Wash, Palo Verde Wash, Fault Wash, the Cut Across Trail, and up the San Felipe Wash. They recorded at least some germination in five locations shown in Fig. 1, as well as noting no germination in three locations shown in Fig. 1.

On 3 December 2018, Fred and Carla did another car tour along San Felipe Wash, and then to Pole Line Road, and exploring the Pole Line Road area. They found the best germination of any Badlands Area on the north side of the East Butte, from the Buttes Pass Road to the end of the East Butte. The germination was primarily in the washes that drain the East Butte.

Links to Other Webpages, etc. on Anza-Borrego Desert State Park Blooms

Anza-Borrego Wildflowers Bloom Report by Fred Melgert and Carla Hoegen, often with daily wildflower updates.

iNaturalist observations in the Borrego Desert since 1 December 2018 (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. 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 © 2008-2018 by Tom Chester, Fred Melgert, Carla Hoegen, Nancy Accola, Don Rideout, Kate Harper, and Birgit Knorr.
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 9 December 2018