What should onions not be planted near?

Answered by Stephen Mosley

Onions are known for their ability to enhance the flavor of their companion plants, but it’s important to note that there are certain plants that do not thrive when planted near onions. It’s always good to have a well-planned garden layout to ensure the success of your plants. Here are some plants that should not be planted near onions:

1. Peas: Onions and peas do not make good neighbors in the garden. Peas are nitrogen-fixing plants, which means they have the ability to convert nitrogen from the air into a form that plants can use. Onions, on the other hand, do not require as much nitrogen and can actually inhibit the growth of peas. It’s best to keep these two plants separate to allow both to thrive.

2. Pole Beans: Similar to peas, pole beans are also nitrogen-fixing plants. They have a symbiotic relationship with certain bacteria that convert nitrogen into a usable form. Onions, with their lower nitrogen needs, can interfere with this process and hinder the growth of pole beans. It’s recommended to avoid planting these two together.

3. Bush Beans: While bush beans do not have the same nitrogen-fixing capabilities as pole beans or peas, they can still be negatively affected when planted near onions. Onions release a chemical called an allelopathic compound, which can inhibit the growth of other plants. This allelopathic effect can be detrimental to the growth and development of bush beans, so it’s best to keep them separate.

4. Asparagus: Onions and asparagus should not be planted near each other. Asparagus has a deep root system and is a perennial plant, meaning it stays in the ground for multiple years. Onions, being shallow-rooted and annual plants, can compete with the asparagus for nutrients and space. It’s advisable to give asparagus its own dedicated area in the garden.

It’s worth mentioning that these guidelines can vary depending on the specific conditions and needs of your garden. It’s always beneficial to observe and experiment with different companion planting combinations to find what works best for your particular situation. Additionally, considering crop rotation and spacing recommendations can help maximize the health and productivity of your plants.

In my personal experience, I once planted onions near peas, unaware of the potential negative effects. Unfortunately, both the onions and peas struggled to thrive. The pea plants were stunted and produced fewer pods compared to the ones planted away from onions. This experience taught me the importance of researching and planning companion planting combinations to avoid such setbacks in the garden.

To summarize, onions should not be planted near peas, pole beans, bush beans, or asparagus. By keeping these plants separate, you can ensure the optimal growth and productivity of your garden.