What Is Companion Planting – All You Need To Know

What is Companion Planting? Read on to Find Out!

Companion planting gets talked about a lot and can be very useful, but equally a lot of claims are made for it that don’t work out in reality. This is because very few people have gone about looking at it scientifically – most of us don’t have the space to be growing multiple combinations of things, to find out what changing one variable might do to make companions actually helpful.

So, the reality is that there are a lot of myths about what worked for one person in one particular situation, as if that should apply to all and sundry, whatever different conditions apply!

This article is what worked for me and what didn’t, with the caveat that I grow in containers or in raised beds, using homemade compost and occasional additions of manure or coco coir.

Also I live in the effete South of England, so I don’t have to cope with the harsher conditions elsewhere in the country! And I grow in my garden, with limited space and no greenhouse, in an urban area.

In this article, I’m going to have a look at what is companion planting, including types of companion planting, main vegetable plants and their companion plants and more…

Table of Contents: What is Companion Planting?

What is Companion Planting: Types of Companion Planting

Whether you’re gardening on a budget, are a beginner or an experienced gardener, you’ll have come across the concept of companion planting.

In this section, let’s have a look at some of the different types of companion planting available.

• Some companion plants are said to attract beneficial insects, like pollinators or insects that eat pests.
• Some companion plants are said to deter pests, like insects that attack plants, at the roots, stems, leaves, or flowers.
• Some companion plants are said to encourage growth in the main veg plant they are planted near.

Sometimes the companion plant is another type of vegetable plant, sometimes it’s a flowering plant. Then there are the companions you need to beware of, as they make it difficult for your main veg plant to thrive.

What is Companion Planting: Perennials as Companion Plants

Some of the companion plants used are perennials, so if I’m using one of those, I plant in a pot, so I can move the pot around to wherever* I want it.

But, it would be quite fine to plant the perennial as the main star in a big pot or a bed, then plant the veg plants around it. Basically, it boils down to just a simple design choice!

*I do crop rotation in some of my beds and not in others, so the perennial pots might be placed beside bed A one year and then beside bed B the next year. Crop rotation is both necessary and unnecessary, depending on your approach, so I’m currently experimenting with four beds in a rotation pattern and four different beds with no rotation, but more on that another time...

Main Vegetable Plants and their Companion Plants

Let’s have a look at some of the main vegetable plants along with their companion plants…

Brassicas

I’ve seen a lot about growing hyssop with brassicas, but getting hyssop to grow has been a problem – though I keep trying!

Instead I’ll put a pot of some strong smelling herb beside the bed/pot I’m growing brassicas in, like oregano, rosemary, sage or thyme.

The great thing about those particular aromatic herbs is you can usually buy a “fresh living herbs” pot from a supermarket quite cheaply, then just repot them into a sturdier pot, giving the herb a bit of space to grow.

Buying perennial herb pots makes sense, as they can be used year after year, without needing to buy more. As an added bonus, it’s easy to snip off leaves from the herb plant for using in cooking, as and when you want.

Beans and Peas

I’ve been used to growing marigolds with my beans, as they’re said to deter pests, but I’m not convinced that they work without huge numbers.

This isn’t exactly feasible in my small space. So, I tend to plant some token marigolds and some other things. 

One year, even with marigolds planted around them, my beans were black with aphids. I left them for a couple of weeks, just picking the beans and putting them straight onto the compost, so the plant would keep producing more beans.

After those couple of weeks, ladybirds turned up and made short work of those aphids and I was happy to be able to harvest my beans for months afterwards!

Last year I experimented with growing sunflowers and beetroot in the same bed as my beans, while I grew dill and beetroot with my peas. There was an awful lot of dill harvested later and I discovered just exactly how pungent it can get in cooking, so moderation is key.

The sunflowers also grew absolutely huge, so next year I’ll be re-siting those to give them much more support.

I was really surprised that the beetroot around the base of the sunflowers and beans (where they were virtually entirely shaded out) grew to be huge too. In contrast, the beetroot I planted around the peas didn’t have much impressive growth.

Squash

Having read that squash vine borers are deterred by nasturtiums and that nasturtiums also lure pests away from brassicas, I tried growing climbing nasturtiums at some distance away from both of those.

This didn’t seem effective on the brassica pest attacks, though the squash seemed unattacked. I think I’m undecided on the nasturtiums, though the normal ones make great ground cover – the climbing ones didn’t climb much.

With my nasturtiums I planted amaranth, which I was pleasantly surprised at the growth of – I had some free seeds!

So this year I’ll be planting different amaranth types to see which I like best, as a main vegetable option, apparently the leaves are used in Carribean cooking and certainly the plant looks beautiful!

When it comes to squash, there are new seeds on sale now for growing squash in containers and I’ve bought some to have a go.

Normally I grow tromboncino squash (see image above) as they grow four feet long and keep for months after harvesting, but I think the idea of container squash is so neat, that I really want to try growing some.

Squash is also a great plant to grow upwards if you are looking for some options for vertical gardening.

Root Vegetables

When it comes to root vegetables, I grow carrots in pots, because pots can be raised higher up, making it harder (though not impossible) for carrot fly to access.

I did dabble with parsnips, but I decided the overwhelming parsnip flavour was too much for me and I prefer the more insipid frozen ones from the shops.

Alongside my carrots I grow coriander, which I love! If I’m growing carrots in pots, I’ll grow lots of closely packed coriander plants in a container beside it.

I initially tried planting coriander beside my carrots in raised beds and found it awkward to snip around the carrot foliage to get to the coriander foliage.

You’ll notice I haven’t mentioned planting carrots with chives as companions, but that’s because I tried it and it didn’t seem to have much effect.

A lot of companion planting is like that – it’s all about trial and error!

Tomatoes and Leeks

Normally I grow tomatoes with borage, basil, or leeks.

Borage is self-seeding and reappears all around my garden. Not to worry, it’s very easy to pick out the whole plant when it’s young and it all makes good compost, especially if there’s a lot of them popping up.

Borage and basil are supposed to repel tomato pests, but I can’t say I particularly was bothered by them.

For me, the main problem last year was tomato blight. Once blight hits – it looks like mottled darker patches on the tomatoes – all you can do is cut off the stem and compost the plants.

I use leeks as companions to my tomatoes, because I like leeks and they are low growing, whereas tall (indeterminate) tomatoes can grow very high, so a good pairing.

I have also grown short (determinate) tomatoes in pots, but the growth wasn’t great. Even in pots, the tall ones outperformed in terms of producing tomatoes, while the short ones only grew a few actual fruits.

What is Companion Planting: Summary

I hope you’ve enjoyed this article about companion planting. Whether you’re looking to build a vertical garden or a sustainable vegetable garden, learning about companion planting is important to maximise your knowledge.

Companion planting is a great idea, but patience is essential. Everyone should read about it, try out a few of the ideas, decide which of those work (or don’t), then the next year keep the companions that work and try out a few more.

That way, over time you’ll build up a picture of what works for you with a range of companions suited to your conditions.

The most important thing is to relax and have fun with your planting. Good luck!