no - this is false. The source you found on Google is wrong.
Genetics, and environmental (warm enough to process/metabolise food, length of day (artificial or natural) /husbandry (stress, quality of food, sufficient heat, sufficient UVA AND UVB) and amount of food provided whilst young and growing are the only things that influence the amount a beardie will grow.
I think that is just an old tale. Years ago I had a baby dragon in a 10 gallon tank. He grew. I then put him in a 20 gallon. Still grew. Finally, upgraded to adult tank. If you feed them properly and provide proper heat and lighting they will grow.
Thanks for that. One of my bearded dragons is around 8 to 10 months old and is in a 4ft x 2ft viv and seems to be doing well. He has 2 uvb lights strips, one 2.0 and other 10.0 and a 100 watt basking light. I feed him rocket, choy, butter nut squash, dandeloin, bit of cabbage and apple along with dusted crickets and dubia roaches, so he should grow fine i hope.
I just set Swordtail's timer for his bath and paused it so I could actually fill his soaking bowl up and he crawled over my phone and canceled the timer
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!