Originally Posted by Skipster
The hybrid term certainly can apply to some varieties, but you're right that it does not apply to all. However, in this case, 'Thermal Blue' and 'Thermal Blue Blaze' are true hybrids -- they are crosses between Kentucky bluegrass (Poa pratensis) and Texas bluegrass (Poa arachnifera).
Because Poa species are largely apomictic, they don't usually cross interspecifically in nature. In fact, the man who pioneered sexual hybridization of Poa species, Dr. Reed Funk of Rutgers University, passed away just this week. Anyhow, the crosses only haveto be made once, then the seed produced by the daughter plants is always genetically identical to the parent, so the cross doesn't have to be done every year.
This isn't the case with all plants, though, as some are only incrossers, some are only outcrossers, and others have a blend of the three.
Very nice explanation. I have read that this hybrid took on traditional physical bluegrass characteristics yet has the heat tolerance of texas bluegrass and has been tested in the deep south with good results. In my area if these findings are true Thermal Blue could be a game changer around here. Everything here is TTTF and I have never seen a lawn that did not have bare are weak spots by late summer.
I feel with a good stand of Thermal Blue mixed in with the TTTF these bare and weak areas will still occur but will naturally fill back in come fall. Also with a healthy stand of Thermal it may help minimize turf tearing due to the dense shallow root system of bluegrass.