Buzz
Onions are a versatile and easy-to-grow vegetable that are commonly used in a variety of dishes. If you have an onion bulb, you don't need to grow onions from seeds. Simply cut off the bottom of the bulb and plant it in the soil. Over time, with patience and plenty of water, you can harvest onions in 90-120 days.
Steps
Prepare the Onion Pieces
Cut about 2.5 cm from the bottom of the onion bulb. Place the onion on a cutting board and use a sharp knife to slice off the bottom and peel off the outer skin. Your onion piece should be around 2.5 cm long to ensure strong growth.
- If planting outdoors, it's best to start in early spring. For indoor planting, you can do this any time of the year.
- You can use most types of onions, including store-bought ones. This method works best if you have fresh, non-rotten bulbs.
Allow the bottom of the onion bulb to dry for 12-24 hours. After cutting the onion, discard the remaining part and place the bottom of the onion bulb on a dry surface with the cut side facing up. Let the piece dry for a day until it feels firm and dry to the touch.
Insert toothpicks into each side of the bottom of the onion bulb. Divide the onion piece into four parts, then insert a toothpick into each section about halfway down. Position the toothpicks evenly so that they form an 'X' shape.
Place the onion bulb over a small bowl of water. Fill the bowl with water up to the brim and place it on a flat surface. Place the onion bulb on top, making sure the bottom just touches the water's surface, and leave it for 3-4 days. Plant the onion when you see small white roots forming.
Planting the Onion Piece
Fill a plant pot with well-draining soil. Visit a nursery to buy a well-draining soil mix and a wide pot with drainage holes at the bottom. Fill the pot halfway with soil – you'll top it off after planting the onion pieces.
- If your garden soil drains well, you can plant outdoors.
- Test the drainage by digging a 30 cm deep hole and pouring water into it. If the water drains within 5-15 minutes, the soil has good drainage.
Place the onion piece in the soil and cover it with dirt. Once the small white roots have grown from the bottom of the onion piece, place it in the center of the pot. Add soil to cover the remaining portion of the onion, leaving about 2.5-5 cm from the top of the pot.
- Depending on your preference, you can keep the pot indoors or place it outdoors when the weather is warm and sunny.
- If you plant the entire bottom of the onion in one spot, you'll likely get more than one onion sprout, but they will grow too close together and won't develop well. Each slice of onion can grow about 1-6 sprouting onions, and you may want to cut the pieces in half as shown in the image. To ensure multiple healthy plants, use a sharp knife to cut the onion bulb into several sections, each with some roots.
Water the onion pieces immediately after planting. Watering will help the onion pieces adjust to their new environment and promote faster root growth. Water just enough to moisten the soil, but avoid over-wetting it.
Spray nitrogen fertilizer onto the soil after watering. Onions thrive in soil with a high nitrogen content. Spray nitrogen fertilizer directly onto the soil and mix it in with your hands to provide the nutrients necessary for the onions to grow.
- You can find nitrogen fertilizer at most garden centers and nurseries.
- Check the label to determine the appropriate amount of fertilizer to apply to the soil.
Taking Care of the Onion Plants
Water the onions with about 2.5 cm of water each week. Onions need plenty of water to grow strong and produce more bulbs. Check the soil daily—if it feels dry to the touch, water it until the soil becomes moist.
Regularly remove weeds if you're growing onions outdoors. Onion plants struggle to compete with invasive plants, and weeds can absorb water and nutrients that are crucial for onion growth. You should frequently check and pull weeds as soon as they appear.
- Avoid spraying weed killers near onion plants, as most weed killers will kill both weeds and crops.
- Inspect for small insects or pests on your onion plants and spray with non-toxic, plant-friendly insect repellent if any are found.
Fertilize the onions every two weeks. Regular fertilizing will help your onion plants grow large and healthy bulbs. Spray a nitrogen-rich fertilizer at least twice a month until the onion bulbs start to emerge from the soil.
- Stop fertilizing once the onion bulbs begin to appear, and continue until harvest.
Harvest the onions when the plants begin to flower. Once your onion plants start to bloom, it's time to harvest. Use a shovel to loosen the soil around the bulb and gently pull the onion out by its leaves.
- On average, onions grown from onion pieces take about 90-120 days to form new bulbs.
Steve Masley
Organic Gardening Expert
Organic Gardening Expert
Can you cut the onion leaves? Pat Browne and Steve Masley from Grow it Organically state: "You can harvest the onion leaves whenever you want, but if you want the bulb to grow larger, it's best to leave them. Each onion leaf contributes a layer to the onion bulb, so if you have 8 or 10 leaves, the bulb will develop 8 or 10 layers."
Advice
- If you initially plant your onions in containers, you can always move them to an outdoor garden later on.
- As long as they are well cared for, your onion pieces will produce bulbs just as successfully as onions grown from seeds.
- Remember to tend to your onions and remove weeds!
- To keep your onions fresh for months, proper storage is key.
Warning
- If your onion plants appear weak, discolored, or unhealthy, they might be diseased. You should separate the affected plants from the others and consult with a nursery professional to determine the best treatment for the illness.
