Bloom Reports from the Anza-Borrego Desert: 2012-2013

California matchweed, Gutierrezia californica
Photograph of flower of Gutierrezia californica
California trixis, Trixis californica
Photograph of flower of Trixis californica
Pictures taken on 2 January 2013 in Plum Canyon.

See also Pictures shown here on prior dates.

See Bloom Reports from the Anza-Borrego Desert for an introduction to this page, extensive general information (not specific to this year) about Annual Germination, Growth and Blooms, including what influences the duration and extent of the annual bloom, photo galleries, and links to other webpages giving information on Anza-Borrego Desert State Park Blooms.

Summary of Annual Germination, Growth and Blooms in 2012-2013

As of 27 January 2013, this year is now the worst bloom year in the past five years that we have been tracking the bloom numerically, and the worst bloom year since the severe drought year of 2005-2006. The plots here show the sad story: Number of Species and Plants in Bloom On Each Trip: 2012-2013. We are scraping along the bottom of the plot for the # plants in bloom for each trip, and have the only curve that has not yet turned up for the # species in bloom for each trip.

However, there is hope for at least some bloom in a few areas. Although most areas, such as the area along the Montezuma Grade of S22, still mostly look like they do in late summer, completely dormant, we finally observed decent germination in the canyons south of Yaqui Meadows on 27 January 2013. The drainage southwest of the Glorietta Canyon parking area has abundant annuals, which increase in number heading up toward Wilson Peak. These annuals germinated in the 13 December 2012 rain, and the 26 January 2013 rain will help them grow bigger and germinate more plants. However, outside the washes, the germination even in this area is poor. Glorietta Canyon itself above the wash has only scattered germination.

We don't know yet whether the germination elsewhere was delayed due to the cold spell in late December / early January, or whether the 13 December 2012 rain favored the Pinyon Ridge area.

Prior to the 27 January 2013 observation of abundant annuals, we observed only scanty germination at the desert's westernmost edge in the San Felipe Valley and Sentenac Canyon, and in widely-scattered parts of Henderson Canyon. In Henderson Canyon on 1/12/13, the main wash had scattered babies of whispering bells, Emmenanthe penduliflora, just producing their first true leaves. Shady spots under boulders in the upper canyon hold hundreds of plants of white fiesta flower, Pholistoma auritum var. arizonicum, also producing their first true leaves.

Farther west, Culp Valley is green from annual germination, but most germination is of two non-native species: redstem filaree, Erodium cicutarium, and red brome, Bromus madritensis ssp. rubens. We observed a few prickly poppies, Argemone munita, on 21 December 2012 in Shelter Valley, and a handful of white fiesta flowers, Pholistoma membranaceum, on 8 January 2013 in Sentenac Canyon. Mike Crouse found decent annual germination in one wash next to the Mexican border in the El Centro area in Imperial County on 18 December 2012 and on 22 January 2013.

It is likely that annuals this year will be present in significant numbers only in the higher elevations on the west side of Borrego Springs which receive more rainfall than the desert floor. As of 28 January 2013, the desert floor has only received 0.75-1.2 inches of rain since 1 September 2012, mainly in two roughly equal events on 13 December 2012 and 25 January 2013. The first rainfall event wasn't enough to germinate annuals except possibly along roadsides and other places with similar runoff. It remains to be seen whether the second rainfall event will germinate any more annuals.

Normally, annual germination on the desert floor occurs in late December or early January, and we are well past that time, pretty much eliminating the possibility that this will be a good bloom year. But the fat lady hasn't sung yet; we could still have a decent bloom year if significant rain falls by mid-February. February and March rains can still germinate annuals, but unless rain continues to fall regularly after that germination, those rains will only produce tiny annuals with a few small flowers.

See also:

Predictions for This Year

At minimum, there will probably be decent flowers in the canyons on the north side of Pinyon Ridge. Elsewhere, we're still waiting to see what happens from the 25 January 2013 0.4-0.8" of rain.

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Copyright © 2008-2013 by Tom Chester, Kate Harper, and Mike Crouse.
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Updated 29 January 2013