Will this grow in hot areas like florida? Some of my plants cant survive summer here. Your plant looks healthy. I would like to have one like that...I'll keep an eye on this.
I can only say that that it took the same amount of time as the plants I had planted directly in the garden. Peppers are great in gallon jugs but they won't get quite as big as those in the soil. Close though. That pepper plant pic was taken AFTER I had already picked some peppers off it!
In my region, Southern Illinois, peppers (and tomatoes...) take anywhere from 3 - 4 months from seed to fruit. Closer to 3 if bought as a young plant from the nursery and closer to 4 (or more) if planting from seed.
I've grown all kinds of peppers in gallon jugs. Just cut around the top keeping the handle intact (that's another neat part about using gallon jugs) and then punch some holes in the bottom using a stake or something similar.
Typically store bought Jalapenos are green--making them unripe. In green Jalapenos as well as any other unripe pepper the seeds are usually not fully developed enough to germinate. If you see red Jalapenos at the grocery store then there is a chance you can grow them. Also the germination rate is better if the pepper was ripened on the plant.