Now that you know what works with onions, it’s time to cross these plants off your list. Chastain discourages gardeners from planting the following alongside onions:
Legumes: “Legumes, like peas and beans, don’t like some of the compounds that onions release. It keeps them from properly absorbing the nitrogen in the soil so they just won’t grow well.”
Aromatic herbs: “Even though onions are aromatics, aromatic herbs like sage, rosemary, basil, oregano and lavender won’t thrive near onions because they compete for the chemicals in the soil they need to grow.”
Asparagus: “Asparagus and onions are terrible bedfellows because their roots fight for space under the soil. They are also both nutrient hogs. It’s best to just give them their own bed with their own blanket of soil.”
