Well - that is a "every tractor is different" , oh and if you have a DPF:
Even though the engine is running and the glow plug indicator is not illuminated in the dash, the glow plugs will cycle anywhere from 3 to 5 minutes after start up. This helps reduce the amount of start-up emissions by 60 percent and also helps reduce build up of soot that would typically be trapped in the regeneration filter (DPF).
Automatically cycled glow plugs = longer times between regeneration.
I took possession of a 2015 Branson yesterday, and every time I have started it - the glow plug indicator illuminates, and it has not been below 50 degrees.