How to Fertilize Onion Plants

Onion plants are hardy, withstanding temperatures of as low as 20 degrees Fahrenheit. They grow underground as the root of the plant and, depending on your tastes, the bigger they are, the better. Small onions tend to have a more concentrated, bitter flavor, while larger onions have a sweeter taste. To encourage your onions to grow large and healthy, make sure you fertilize them properly.

Things You'll Need

• Nitrogen and phosphorous rich fertilizer
• Mulch
• Water

Instructions

1. Dig a trench 1 inch deeper than required to plant onion seeds and sprinkle a 1-inch layer of fertilizer on top of the soil. Plant seeds, cover and water generously.

2. Wait until green shoots begin to sprout above the soil. Spread half an inch of fertilizer around the shoots. Mulch another half inch and water thoroughly, but not so the soil is soggy. The mulch and water will help carry the fertilizer to the plants.

3. Layer about an inch of fertilizer around each onion plant every four weeks. Onions require very nutrient-rich soil to grow, so follow this regular fertilization schedule strictly.

References

• Onions
• Onion Planting
• Grow and Care: Onions