Answers. Best Answer: garter snakes are mainly diurnal (daytime) but if the weather is hot than they will comme out during the evening. Additional information-they grow to be any where between 2-4 ft though they could get to be 5 ft.-females are larger than males.nswers. Best Answer: garter snakes are mainly diurnal (daytime) but if the weather is hot than they will comme out during the evening. Additional information-they grow to be any where between 2-4 ft though they could get to be 5 ft.