'Plant them together!' These two popular vegetables grow so much better next to each other

Companion planting can have a host of benefits, and these two vegetables are a perfect pairing

Carrots and onions growing together in soil
(Image credit: Getty Images)

If you're a seasoned gardener you'll be familiar with the concept of companion planting. For the rest of us, the clue is in the name. This nifty idea is all about growing particular plants together in order to reap a host of benefits, from improved soil fertility to pest control, and two of our favorite, most-used vegetables are a perfect pairing - carrots and onions. 

While you won't be growing either vegetable right now, you'll certainly be eating them. This time of year marks the return of casseroles, pies, and winter stews, and carrots and onions are core ingredients in all of the above. Whether you're looking to start your first modern vegetable garden or you just want to take next year's crop to the next level, planting these two tasty ingredients next to one another is the best place to start. Here's what you need to know. 

What is companion planting and how does it work?

Tops of carrots and onions growing together in soil

(Image credit: Getty Images)

Companion planting isn't reserved for experts only. This gardening trick is just as useful for beginners. 'It refers to the practice of growing certain plants together to take advantage of their mutual benefits,' explains Tony O'Neill, professional gardener and owner of Simplify Gardening. 'These benefits can range from pest control and improved growth to enhanced flavor and yield. Essentially, it's about creating a symbiotic relationship between different plants to promote healthier gardens.'

The one catch is knowing which plants work best together, and while it might take a bit of research, the benefits are well worth the extra effort. 'Think of it as nature's way of creating perfect pairings,' notes Lina Colwey, blogger at Trimmed Roots. 'By harnessing the power of plant relationships, you can create a garden ecosystem that promotes healthier plants, deters pests naturally, and increases overall yields.' 

Why is planting onions and carrots together a good idea? 

Carrots and onions that have just been harvested laying on a bed of soil

(Image credit: Getty Images)

As it turns out, carrots and onions go together just as well in the ground as they do on your plate, and both are great vegetables for beginner gardeners to grow. The discovery is nothing new - seasoned gardeners have been taking advantage of this pairing for centuries. The question is, 'why?'  

'Planting onions and carrots together is a match made in gardening heaven,' says Lina. 'These two root vegetables complement each other beautifully because onions emit a distinct scent that repels many pests, including carrot flies. By interplanting onions and carrots, you create a natural deterrent system, keeping those pesky flies away from your precious carrots. It's like having a built-in bodyguard for your plants!' 

'Onions can also help deter slugs and snails, which are notorious for munching on tender carrot seedlings,' adds Lina. 'By surrounding your carrots with onions, you create a natural defense system against these slimy intruders.' 

Beyond mutual pest control, there's also a whole load of other benefits that come with planting carrots and onions together. 'This pairing can promote more efficient use of garden space, perfect for small gardens,' says Tony. 'As onions don't need as much surface space (since they grow vertically with their shoots), carrots can easily spread out below. This allows gardeners to optimize their garden real estate.'

The difference between onions' fibrous root systems and carrots' taproots also plays a part. 'Onions have more shallow root systems while carrots go deeper into the soil,' Tony notes. 'This means they aren't directly competing for the same nutrients, ensuring both get ample sustenance.'

What time of year should you plant carrots and onions? 

Carrots and onions growing next to each other in soil

(Image credit: Getty Images)

Fall might be a time to enjoy the fruits of your labor after harvesting your crop, but - unsurprisingly - now's not the time to be growing these two vegetables in your backyard.

Tony explains that carrots and onions both thrive in cooler weather, making early spring a good time to plant them for most hardiness zones. 'While onions can handle a bit of frost, it's ideal to plant them as soon as the ground is workable,' he says. 'Carrots, on the other hand, are best sown a couple of weeks before the last frost date. In essence, both can indeed be planted around the same time, but just ensure the soil is well-draining and loose enough to cater to the growth needs of both plants.' 

While carrots are best planted directly into your soil (using a nifty carrot planting hack that makes it easy to distribute the seeds), Lina suggests starting your onions indoors in late winter or early spring before transplanting them outdoors after the threat of frost has passed. 'This staggered planting approach allows you to maximize your harvest and enjoy a continuous supply of fresh produce,' she says. 

'While onions and carrots can be planted around the same time, keep in mind that onions take longer to mature compared to carrots,' Lina adds. 'Therefore, it's crucial to plan your planting schedule accordingly to ensure a successful harvest.' 

Keen to up your gardening game? Companion planting is an easy skill to apply, and growing your onions and carrots together in spring will guarantee a bumper crop that will feed you throughout all of fall! 


♬ Idea 9 (Slowed + Reverb) - Gibran Alcocer
Color & Trends Editor

Lilith Hudson is the Color & Trends Editor at Livingetc. Writing news, features, and explainers for our digital platform, she's the go-to person for all the latest micro-trends, interior hacks, and color inspiration you need in your home. Lilith discovered a love for lifestyle journalism during her BA in English and Philosophy at the University of Nottingham where she spent more time writing for her student magazine than she did studying. After graduating, she decided to take things a step further and now holds an MA in Magazine Journalism from City, University of London, with previous experience at the Saturday Times Magazine, Evening Standard, DJ Mag, and The Simple Things Magazine. At weekends you'll find her renovating a tiny one-up, one-down annex next to her Dad's holiday cottage in the Derbyshire dales where she applies all the latest design ideas she's picked up through the week.