You don’t need a garden center to start growing your own onions. A single red onion from your kitchen can produce dozens of new ones, with nothing more than a glass of water, a pot of soil, and a little patience. This simple propagation method turns what you would normally throw away into an endless supply of fresh onions.

Onions are biennial plants that naturally want to regrow. The root base contains dormant buds that, given the right conditions, will sprout into independent plants. By separating these shoots as they grow, you can multiply a single onion into a whole row.

Step-by-Step: Regrow Onions from a Base

What you need

• 1 fresh red onion (or any variety)
• A glass or jar
• Water
• A small pot with potting soil (or a garden bed)

How to do it

Step 1: Prepare the base
Slice the onion horizontally about half an inch from the root end. Keep the root base intact – this is the part that will sprout. Use the rest of the onion for cooking.

Step 2: Grow roots in water
Place the onion base, cut side up, into a glass or jar. Add enough water to cover the bottom quarter inch of the base – do not submerge it completely. Set it in a sunny windowsill. Change the water every two days. Within a few days, white roots will begin to grow downward and green shoots will emerge from the center.

Step 3: Plant the base
Once the roots are about 1 to 2 inches long and the shoots are several inches tall, transfer the base to a small pot filled with moist potting soil. Bury it just deep enough to cover the roots, leaving the green shoots above the soil.

Step 4: Separate new shoots
As the shoots grow taller, you will notice they are actually individual plantlets emerging from the original base. Gently pull them apart, making sure each shoot has some roots attached. Replant each separated shoot into its own small pot or directly into a garden bed, spaced about 4 to 6 inches apart.

Step 5: Harvest
Keep the soil consistently moist and give the plants plenty of sunlight. In about 8 to 12 weeks, each shoot will develop into a full-sized onion. You can harvest them earlier for green onions if you prefer.

Why this works

Onion bases contain meristematic tissue – cells that are programmed to produce new growth. By providing water and light, you activate these cells. By separating the shoots, you allow each one to develop its own root system and bulb, multiplying your harvest exponentially.

What you might notice

Within the first week, roots and shoots appear rapidly. After separation, each plantlet will establish itself quickly in soil. Within a few months, you will have a continuous supply of fresh, homegrown onions.

A few tips

Use fresh, firm onions – older or sprouting onions work too, but may be less vigorous. Change the water regularly to prevent rot. Once planted, keep the soil moist but not waterlogged. You can repeat this process indefinitely using the new onions you harvest.

A simple, self-sufficient habit

One onion, a glass of water, and a little soil – that is all it takes to start growing your own food. This method is free, easy, and endlessly rewarding. Try it once, and you may never buy onions again.

For more clever kitchen tricks, check out how to make the simple morning mix that boosts vitality or the simple kitchen mix that does something unexpected, and don’t miss the kitchen root trick that transforms hair naturally!