Katie's diligent care in watering and fertilizing the cabbage seedling led to the growth of an enormous cabbage, demonstrating the effects of attentive gardening practices.
The connection between Katie's watering and fertilizing of the cabbage seedling in paragraph 1 and the enormous size of the harvested cabbage mentioned in paragraph 2 is that Katie’s great care of the seedling led to the cabbage's enormous growth.
Her diligent gardening practices, such as properly watering and providing the right nutrients through fertilization, would have allowed the cabbage to grow larger than it might have under less attentive care.
The result of these actions is an exceptionally large cabbage, demonstrating the importance of consistent care in gardening.