BTW, we leave the bacon out of the stuffing & actually wrap a half/whole slice of bacon around the stuffed jalapeno.
I leave most of mine on the plant until they start turning red (for jelly) ... first they get sort of 'black' before going to red. I take them off the vine when I see them starting to turn & let them finish inside. I use only red ones for Jalapeno Pepper Jelly - the jelly ends up the most gorgeous amber color. If you make the jelly out of green ones, the color is a 'muddy' green & green food coloring is generally used to brighten up the color.
If your jalapenos get 'old' on the plant, even as they turn red, they get sort of 'age' lines .... I don't know how else to describe it. I'd pick before they get 'lines'.
You may want to leave a couple on your plant & watch the process & then you'll have an idea of what they do as they 'ripen'. You could also take a look at jalapenos in the store - that would give you an idea of 'size'.
Some pictures:
Notice top right - pepper turning - green goes blackish, then goes to red - the one on the very far right, mostly red, has some 'age' lines.
Jalapeno pepper jelly color when you use red peppers.
