How to Root an Onion

Root onion cuttings can produce new onion plants.

Growing onions can be a worthwhile pastime that will constantly supply your kitchen with a fresh crop. Onions are traditionally grown from seeds or sets, but another method for producing these flavorful vegetables is by root cuttings. Save the bottom that contains roots of the next onion you eat and use it to produce a new plant. Although this method is simple, it takes time and patience before the onion will be ready to harvest and enjoy.

Things You'll Need

• Onion
• Bowl
• Water
• Rocks
• 6-inch plastic pot
• Potting soil

Instructions

1. Prepare the onion cutting. Cut off the bottom portion of an onion that contains the roots. Leave 1 1/2 to 2 inches of the onion's flesh attached to the root section.

2. Place the onion cutting in a shallow bowl with the roots facing downward. Use rocks to anchor the onion against the side of the bowl so the roots will remain facing down. Add tap water to the bowl until the onion cutting is completely covered.

3. Place the bowl in a sunny area. Position the container so it is sitting in full sunlight if possible, otherwise set it in a well-lit room. The more sunlight the onion cutting is exposed to, the faster the roots will grow.

4. Check on the onion cutting every two to three days. Add additional water to the bowl as the existing water evaporates. Keep the onion cutting completely covered with water until it begins to grown. Reduce the water level so only the root portion is submerged once new roots begin to develop.

5. Fill a 6-inch plastic pot 2/3 full with potting soil. Transplant the onion start into the soil once a healthy root system has developed. This often occurs two to three weeks after the cutting was made. Place the onion start, root side down on the soil in the center of the pot. Cover with one to two inches of additional potting soil. Water the pot thoroughly until water is running from its bottom. Place the pot in a sunny window.

6. Water the potted onion when the top one inch of soil becomes dry. Transplant the onion into an outdoor garden plot once it has grown a few leaves. Cut the leaves down to 1/3 of their height, remove old onion scales from the bulb. Plant the bulb in the ground with the leaves above the soil surface. Water the onion every few days at first so the roots become established. Fertilize the onion weekly. Harvest once the bulb has reached the desired size.

Tips & Warnings

• The onion can be left to grown indoors in the container if desired.

References

• Sustain Lane: How to Grow Onions from Discarded Onion Bottoms
• Mother Earth News: Growing Green Onions
• Urban Organic Gardener: Growing Green Onions From Green Onions in Your Kitchen