Onion Facts

Learn fun onion facts and general information about onions. This page includes how onions grow, what to look for when buying them, storage tips, an onion growing experiment, nutrition facts, and easy onion recipe ideas.

Kids Cooking Activities Teaching Materials

Teaching kids to cook? Save time with ready-made lesson plans used by parents and teachers. Browse teaching materials →

This post may contain affiliate links. We may earn a small commission at no extra cost to you. Learn more.

Fun Onion Facts

Onions are available year round.
Onion bulbs grow underground, while their green tops grow above ground.
There are different varieties of onions, including bulb onions and green onions.
Onions add flavor to many cooked dishes.
Onions can even sprout again from leftover pieces in a simple experiment.

How Onions Grow, Buying Tips, and Storage

When Onions Are Available

Onions are available year round.

How Do Onions Grow?

Onion bulbs grow underground, while the green tops grow above ground.

What to Look for When Buying Onions

Many varieties are available, but choose onions that are firm and not soft when pressed.

Onion Storage Tips

Store onions in a dark, dry place. If you grow or harvest many onions, they can be stored bunched together in a well-ventilated place.

Kid Tip: A food chopper can help make chopping onions easier and may reduce tears.

How to Cook with Onions

How to Use Onions

Peel the onion and trim the ends.
Chop, slice, or dice it depending on your recipe.
Saute onions and add them to dishes for flavor.

Cooking Tip: Cooking onions slowly can make them softer and sweeter.

Bulb Onions vs. Green Onions

Bulb onions have a round underground bulb and are often chopped into recipes.

Green onions are long and slender and can be used in lighter dishes or as a topping.

Both add flavor, but they look and taste a little different.

Food Science: Why Onions Make You Cry

Why Do Onions Make Your Eyes Water?

When you cut into an onion, tiny compounds are released into the air. When they reach your eyes, they can make them sting.

Your eyes respond by making tears to protect themselves and wash the irritation away.

This is why raw onions can make you cry, but cooked onions usually do not.

Onion Growing Experiment

Grow Green Shoots from an Onion

Cut the bottom root end off an onion.
Place the onion bottom in a shallow dish with a small amount of water.
Set it in a bright place such as a windowsill.
Keep the bottom moist but do not flood it.
Watch for green shoots to begin forming over the next several days.

Within about a week, the shoots may grow taller so kids can observe how plants can sprout again from leftover vegetable scraps.

Onion Nutrition Facts

Onions contain phytochemicals that help keep you healthy.

Onions contain helpful plant compounds called phytochemicals.
They add flavor to meals while also contributing nutrients.
Both bulb onions and green onions can be part of healthy meals.

More Food Fact Resources

Onion Recipes

Onion Rings

Simple onion rings made with pancake mix, corn meal, milk, and sliced onion.

Category: Snack
Prep: 10 minutes
Cook: 2 minutes
Yield: Varies

Ingredients

1 cup pancake mix
1/4 cup corn meal
1 cup milk
1 large onion

Directions

Combine pancake mix, corn meal, and milk and beat until smooth.
Slice the onion and separate into rings.
Dip the rings in the batter, coating well.
Deep fry at 375 degrees for about 2 minutes.

Cooking Note: Deep frying should always be done by an adult.

Caramelized Onion Pasta

Watch the video below for a pasta idea featuring sweet cooked onions.

Steam-Grilled Green Onions

Green onions cooked in foil with garlic, butter, salt, and pepper.

By Emily B., Rhode Island

Category: Side Dish
Prep: 10 minutes
Cook: 5 to 7 minutes
Yield: 4 servings

Ingredients

12 green onions, rinsed, ends trimmed
2 cloves garlic, minced
2 tablespoons butter, cut into small pieces
Salt to taste
Ground black pepper to taste

Directions

Preheat a grill for medium-low heat.
Cut a sheet of aluminum foil about 12 by 15 inches.
Arrange the green onions side by side in the center of the foil.
Sprinkle with garlic, salt, and pepper, then arrange butter over the onions.
Fold the foil into a sealed cooking pouch.
Place the packet away from the main heat source and allow the onions to steam 5 to 7 minutes.

Serving Tip: These make a simple side dish for grilled meals.