Leeks Grow In Harmony With Veg, Herbs And Flowers – These Are Their Best Companions
Elizabeth is a Permaculture Garden Designer, Sustainability Consultant and Professional Writer, working as an advocate for positive change. She graduated from the University of St. Andrews with an MA in English and Philosophy and obtained a Diploma in Applied Permaculture Design from the Permaculture Association.
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
IN THIS GUIDE
Choosing companion plants for leeks and using leeks as a companion plant for other crops, can be beneficial in many ways.
When we use companion plants, we are looking to promote healthy plant growth and create a functioning ecosystem in which plants and wildlife work together, with us, in harmonious balance.
When choosing companion plants for leeks, we need to remember the growing conditions they require and find other plants that like the same or similar growing conditions.
Our aim is also to increase the number of beneficial interactions and boost yield overall, without adversely affecting any plants through excessive competition.
Thankfully, leeks grow well alongside a wide range of other plants.
As alliums (members of the onion family), they can help (through their scent) to repel, confuse or distract a number of pest species.
However, they can also themselves be troubled by pests and planting certain plants nearby can help deal with these specific pest issues.
Vegetable Companions
Cabbage (And Other Brassicas)
Leeks, like other members of the onion family, can be wonderful companions for cabbage and other members of their plant family such as broccoli, kale and kohlrabi.
The leeks may help repel, confuse or distract common cabbage pests like whiteflies and cabbage white butterflies.
Beetroots & Chard
Beetroots and chard also grow nicely alongside both brassicas and leeks.
Leeks may help to deter aphids and flea beetles that might plague your beetroot crop.
The beetroots also help leeks as their roots break up the soil and potentially create a more free-draining situation.
Celery
Celery can also help break down and loosen soil for leeks, while leeks can help to protect your celery from pests such as leaf miners and carrot root flies.
You might also choose to grow leeks in rotation with other alliums such as bulb onions or garlic.
Keeping these close to one another can help make crop rotation easier.
However, remember that these crops share pests, so plant other companions between and among them to mask their scents, and don’t grow them too close, even when they are in the same bed.
Herb Companions
Many aromatic herbs can also help mask the scent of leeks and some of their other vegetable companions and keep them free from pests.
Try lavender, rosemary or thyme around the edges of your bed.
Some even argue (albeit anecdotally) that certain herbs like rosemary and thyme can actually improve the taste of leeks growing close by.
Just remember that leeks like more moisture than these Mediterranean herbs.
Flowering Companions
A number of other flowering plants can also be beneficial for leeks and their vegetable companions when grown close by.
“I often cook leeks in combination with herbs, but I’ve never yet tried growing them together to see if they have a beneficial impact on each other,” shares Colin Skelly, Master Horticulturist.
“I’ve always found that leeks next to brassicas work well, so perhaps there is a positive association, although not enough to deter cabbage white butterflies in my experience!”
Some may help with repelling, confusing or distracting pests, while others can be particularly beneficial because they attract beneficial predatory insects to help keep pest numbers down.
Calendula, French marigolds and Borage are three great companion plants that will help leeks as well as many other plants in your vegetable garden and can be wonderful throughout your kitchen garden.
Bad Companions
While leeks can work well with the above and also with a number of other plants, there are certainly some combinations that are best avoided.
Peas
Peas make bad companions for leeks because they are said to have allelopathic effects on one another – i.e. they stunt each other’s growth.1Evenari, M. (1961). Chemical influences of other plants (allelopathy). Retrieved March 21, 2023, from https://link.springer.com/content/pdf/10.1007/978-3-662-11209-0_6.pdf
Beans
The same is true for beans and other legumes that you might grow in your vegetable garden.
Of course, you should also avoid planting leeks with other plants that do not like the same conditions, as caring for each will become incredibly difficult.
Additional Considerations
Companion planting is often said to be beneficial in a garden and some beliefs of gardeners have been borne out in scientific studies.
However, it is important to realise that there is still a lot that we do not understand about plant interactions, so often, in companion planting, we do not always know how efficacious certain combinations will be.
However, by experimenting with different plant combinations that may work, making educated guesses and avoiding known bad combinations, we can often achieve far better yields and results in our gardens than we could do by planting in mono-crop beds.
We can also help improve things for wildlife that shares our space too, by boosting the diversity of plants growing where we live.
