Ask Mr. Smarty Plants

There are various factors that could be involved so we need to do a little detective work.  Was this the case last spring? Has anything in your front yard changed since last spring; e.g. new sprinkler system, addition of fertilizer, change in  mowing schedule?
 Let’s start by looking at the plants involved. The Indian Paintbrush and the Bluebonnets are both annual plants, and the current crop  depends on the germination of last year’s seeds. The Paintbrush can behave as a semiannual, flowering in the second season. The Speargrass is a perennial. Once it gets established, it will return year after year, and it is hard to get rid of.

Bluebonnets Lupinus texensis (Texas bluebonnet)
Indian Paintbrush Castilleja indivisa (Entireleaf indian paintbrush)  can also behave as a perennial
Speargrass Nassella leucotricha (Texas wintergrass)

I’m going to include several links and previously answered questions that will help us understand the relationships among these three plants.

These links will cover planting bluebonnets and Indian Paintbrush, and hemi parasitism.
Planting
   < http://www.txdot.gov/inside-txdot/division/maintenance/wildflower-program/planting-bluebonnets.html >

  < http://www.bluebonnetlove.com/blog/texas-wildflowers/indian-paintbrush/  >

Hemi parasitism
      <http://www.wildflower.org/expert/show.php?id=3673 >

     < https://www.wildflower.org/expert/show.php?id=2832 >

     < https://www.wildflower.org/expert/show.php?id=2785 >

As we see, the Indian Paintbrush can be a hemiparasite on the Bluebonnets which could account for the difference in the number of plants.The Paintbrush can also parasitize the Speargrass which is a good thing in this case.

If the bluebonnets were mowed before all of their seed were ripe, and the paintbrushes were acting like biennials, you could end up with more paintbrush plants than bluebonnets. So mowing schedules are important. Control of the Speargrass can be affected by limiting the seed source, so a winter mow to knock down the Speargrass before the Painbrush and Bluebonnets are tall enough to be  affected may be in order. I would be reluctant to recommend herbicides in this instance.