As you begin to plan and prepare for your gardens, be sure to select the proper site for your onions. Provide your onions what they need to thrive from the start and you’ll grow a successful onion crop. Whether you plant in the ground or in containers, placing your onions where they will have optimal conditions will give you the best results. Here are some tips on determining where to plant:

Crop Rotation

pink root on onion plant

It’s crucial to not plant onions in the same location for more than three consecutive years. Rotating your crops helps keep nutrients from being depleted in the soil. Over time, onions can also attract a fungus known as pink root. Pink root attacks the root system and prevents the onion from developing properly, resulting in yield loss. Rotating the crop keeps this fungus from surviving in the soil between plantings and keeps the needed nutrients in the soil.  

Sunlight Requirements

Onions prefer full sun, especially during the afternoon hours. The heat and light are necessary for proper growth. Onion plants can’t be grown in full shade, and those grown in partial shade will be smaller and more susceptible to pests and diseases. If you plan to grow tall plants such as corn or tomatoes near your onions, plant them so they don’t shade your onion plants from the afternoon sun.  

Soil Type

Onions appreciate a loose, sandy loam, which allows them to easily expand when bulbing. Their feeding roots need to be close to the surface of the soil. Shallow planting in loose soil will increase bulb size and eliminate the stress caused when the soil is compact. It’s important to keep the soil as loose as possible throughout growing so that bulb formation is not restricted. 

Prevailing Winds

Wet, damp conditions promote disease in your onions. You can help prevent disease by positioning rows in the direction of the prevailing winds. The breezes will help keep the onions and the soil free of excess moisture. Try putting a windsock or pinwheel in the area being considered to note which way the wind tends to blow before you choose the planting site. 

Providing favorable conditions for your onions from the start of the season will help nourish and protect them all season long.