Ugh.... They do not grow that fast..
You can expect a Gator to reach around 18 to 24 inches the first year, then slow to a few inchs or so per year after that. They reach maturity in 5 to 8 years at which time they drastically slow in growth. In your pond you could keep it in there for quite some time (maybe life). I would however suggest you just stick with the spotteds if you wish to have more than one fish in there. Gators are unpredictable and have a nasty habit of killing tankmates (pondmates?) if they so desire. They really are best kept alone or with other gator gar.
Just out of curiosity: what part of Texas are you in?
Ok... thats makes more sense. I'll try to run up the creek and net some baby gar and see if I can't get a Gator Gar. Anyone have a pic of 10" or so Gator Gar?
It'll be fine for at least 2-3 years. I heard they max out around 6 feet in captivity, 10 feet in the wild, though no personal experience with gators past 2ft
gators average out at about 5-7' in captivity and 6-8' in the wild. they have potentail to grow to 10' in the wild but it is rare. and the differences between 'true' and 'fake' gars are pretty apparent. fake gars, commonly called rocket gar, are needlefish, characins, and tetras. they are related to gars in no way. their bodies just look similar. all true gars have a rounded caudal fin.
Rounded heterocercal caudal fin to be exact.... Abbreviate heterocercal to be very correct. This a Caudal type where the vertebrae extends into the upper lobe (edge) of the Caudal.
Some Needlefish (Belonids) have rounded Caudal fins..