Sugar baby watermelon
How large will sugar baby watermelon get when they are ready to be picked?
Columbia County Florida
Most of the seed vendors that I checked indicate 'Sugar Baby' is about 8 inches in diameter when full grown. If your question relates to how to know when they are ready to harvest, here are tips from a popular website:
"First, inspect the curly tendril near where the watermelon attaches at the stem. It should be dead or brown. Second, turn the melon on its side and inspect the belly. The underside of the watermelon should be creamy-white for seeded varieties and golden yellow for seedless varieties."
I hope this answers your question.