Bluebonnet Notes: 2023 Bluebonnet Forecast (Part III) - Texas Hill Country

March 3, 2023  |  Texas Hill Country

Disclaimer: I am neither a botanist nor a meteorologist. I am simply someone who loves bluebonnets and has been hunting them and trying to learn more about them since 2010. I write these each year for myself so that I can have a record of what my thoughts were at the time. If you are interested in my track record for accuracy, my past predictions and reviews from previous years can be found here. Predicting a bluebonnet season is difficult to do with accuracy due to the fact that there are so many different factors are involved in a bloom that are impossible to evaluate. Each wildflower season is unique and presents different opportunities.

In Part I of this series we took a look at the rainfall data from the Big Bend in West Texas and in Part II we looked at the data from South Texas. Now we move on to the Texas Hill Country. For the purposes of this article, the Texas Hill Country is defined as Llano County, Mason County, San Saba County, Blanco County, Burnet County, and Gillespie County.

Though there are many contributing factors for a bluebonnet bloom, the most important by far is rainfall. Below, rainfall maps showing the departure from normal rainfall are presented for each month from September 2022 to February 2023.

Because the purpose of this series of articles is only to attempt to identify the locations that are most likely to have bluebonnets, rainfall is the only bloom factor that is examined.

Seed Germination Period

I believe that rainfall during what I term the seed germination period is more crucial for bluebonnet development than rainfall during any other period. The germination period runs from sometime in September to sometime in November. This doesn't mean that bluebonnet seeds can't germinate during other months of the year, just that this is when the large majority of them will germinate, if they are going to do so.

September 2022 departure from normal rainfall in the Texas Hill Country
September 2022 departure from normal rainfall in the Texas Hill Country
October 2022 departure from normal rainfall in the Texas Hill Country
October 2022 departure from normal rainfall in the Texas Hill Country
November 2022 departure from normal rainfall in the Texas Hill Country
November 2022 departure from normal rainfall in the Texas Hill Country

While rainfall during September and October of 2022 was generally below average across the Texas Hill Country, the above average rainfall of November 2022 may have been enough to germinate a fair number of seeds. The totals in parts of northern Burnet and Llano Counties as well as most of San Saba County are encouraging, and I can confirm that on my own land in central San Saba County there are a decent number of rosettes waiting to bloom.

Rosette Development Period

The rosette development period runs from sometime in November to sometime in February. This is the period when bluebonnet rosettes are going through a process known as vernalization and developing their root structure. While rainfall is still important during this time, it is not as important as it is during the seed germination period.

December 2022 departure from normal rainfall in the Texas Hill Country
December 2022 departure from normal rainfall in the Texas Hill Country
January 2023 departure from normal rainfall in the Texas Hill Country
January 2023 departure from normal rainfall in the Texas Hill Country
February 2023 departure from normal rainfall in the Texas Hill Country
February 2023 departure from normal rainfall in the Texas Hill Country

Rainfall across the Texas Hill Country was below average across the entire rosette development period. This likely means that the majority of plants that sprouted will be smaller and less developed than is ideal.

2023 Texas Hill Country Bluebonnet Forecast

Thanks to the above average rainfall during November I believe that the Texas Hill Country has the best chance to have bluebonnets of the three areas that I cover. As previously stated, on my own land in central San Saba County there are a pretty decent number of rosettes that have sprouted, though none that I have seen are especially large, which aligns with what the rainfall maps show for December, January, and February.

As of this writing (March 3) there are already short stretches of bluebonnets in full bloom along roadsides in Burnet County, which is extremely early and doesn't bode well for bluebonnet season overall. The very warm winter we have had will likely have the same effect across the entire area, so expect blooms to be early everywhere. I expect San Saba County as well as the northern portions of Burnet and Llano Counties to have the best chance for bluebonnets, but don't discount southern Llano County or Mason County either because there's always the chance for a surprise.

2017041501, Cactus, live oak, and Texas bluebonnets
A prickly pear cactus (Opuntia engelmannii) and live oak tree (Quercus virginiana) in a field of Texas bluebonnets (Lupinus texensis) and firewheels (Gaillardia pulchella) in Mason County, Texas.

SOURCES

Merlo, J. (2020, January 11). Contributing factors for a bluebonnet bloom (Part I). Retrieved from https://www.jasonmerlo.com/gallery/contributing-factors-bluebonnet-bloom-texas/

Merlo, J. (2020, January 18). Contributing factors for a bluebonnet bloom (Part IV): Texas Hill Country. Retrieved from https://www.jasonmerlo.com/gallery/contributing-factors-bluebonnet-bloom-texas-hill-country/

NOAA. (n.d.). Advanced Hydrologic Prediction Service. Retrieved from https://water.weather.gov/precip/#

Vernalization. (2019, December 17). Retrieved from https://en.wikipedia.org/wiki/Vernalization