Have you ever heard that if you swallow a watermelon seed, a watermelon will start growing in your stomach or out of the top of your head??
Luckily, this age-old claim is nothing more than a rumor. Swallowing a watermelon seed (or any other type of seed, for that matter) cannot cause you to grow a plant in your stomach, out of your mouth, or anywhere else on or in your body. (Even if a teasing sibling or a prankster uncle tells you otherwise!)
The reason plants can't grow from your body when you eat or swallow their seeds is that your body doesn't provide the right conditions for plant-life. What are some things you've learned about which plants need to survive? Water, sunlight, carbon dioxide from the air, and nutrients (usually from soil) are all essential to a plant being able to germinate and grow! While a seed in your stomach might be able to get some water, it wouldn't be able to get the sunlight, carbon dioxide, or nutrients that it needs and so it would not be able to turn into a plant. Phew!
by Mya Kagan (Whyzz writer)
While it isn't a big problem to accidentally swallow watermelon seeds, there are some plants whose seeds are good to avoid. These include apples, cherries, and apricots. Not only are their seeds usually too tough to chew or too big to swallow, but they contain small amounts of toxins that can be harmful in big quantities. (Luckily, these seeds and pits would be so unpleasant or difficult to eat that it's unlikely you'll ever accidentally eat too much of them!)