Companion planting for weed control


In a previous blog post, we introduced the idea of a natural weed control strategy that focused on the role of soil health and beneficial microbes in effectively suppressing weeds. 

As a quick follow-up, we want to highlight another natural approach that can be used to help stop weeds from getting a foothold in your garden – companion planting.

What is companion planting?

Companion planting is the practice of combining plants with synergistic relationships to achieve a better outcome than planting one species alone. The term is closely related to, and often confused with, other planting strategies such as inter-cropping and mixed-species planting.

In the context of weed control, companion plants are often used to generate greater competition for soil space in situations where one of the species is a relatively poor competitor on its own. By introducing one or more different plants and maximising this competition, weed growth has been shown to be reduced by as much as 60% in some commercial crops (where this type of strategy is regularly employed).

While weed control is one benefit of companion planting, this strategy can also be used to enhance growth through supply of varied nutrients and repel or attract certain insects and microorganisms.

Companion planting examples

When it comes to companion planting for weed control, the primary aim of the game is to take up as much space as possible between the main plants in order to suppress weed growth. 

In flower beds, perennial groundcovers such as bellflower, creeping boobialla and coreopsis are good, hardy options to provide dense coverage and eye-pleasing aesthetics with their stunning flowers. In vegetable gardens, herbs like mint and basil can be added to the spaces around vegetable plants to perform the same function.

Although not necessarily for weed control purposes, other good examples of companion planting species include onions, which use their strong odour to deter numerous pests for a whole host of vegetables, and marigolds, which can repel parasitic worms and other pests while also attracting helpful insects. 

As you might’ve guessed, the effects of companion planting can also work in reverse, so to speak, with some crops having detrimental effects on their neighbours. While good for so many plants as noted above, onions are bad for asparagus as they can release substances that hinder growth.

Companion planting in your garden 

Companion planting can be a great way to naturally suppress weed growth in any garden, however it must be planned properly and done carefully. Make sure you do plenty of research to determine the best plants to use and where to use them. For the best outcomes, you will also need to closely monitor performance and be willing to make some adjustments along the way to find the optimum plant combination.


You can find more hints and tips on companion planting and weed control in our previous post, “What You Need To Know About Planting Flowers In Spring”. Or, if you’re after more direct assistance with companion planting practices for you garden, please get in touch with the team at Bioweed today.