Companion Planting

What is it really?

Companion planting is SO much more than just putting basil with tomatoes or adding in nasturtiums, calendula & marigolds between plants. Yes both of those are great to do (and I do those too). Companion planting is great to use as a way of having sacrificial plants or ‘trap crops’. Plants to protect other plants – carrots and onions are a classic, carrot fly gets deterred by onion smell, and onion fly by the scent of carrots. They are keeping each other safe and by doing so they produce better.

Companion planting is a beautiful way of interplanting your crops. By doing so, combining vegetables with flowers and herbs, you create small little eco systems. You’ll attract good bugs to eat the bad, pollinators to pollinate your crops, limit the spread of disease because there’s not a mono culture of the same thing (rows and rows of singular vegetables for instance, which will be more susceptible to disease).

Creating these little eco systems is one way to start a food forest. This is companion planting on a slightly larger scale as you’ll have tree(s), shrubs/bushes, low growing and ground cover plants. This could be a fruiting tree, fruit bushes & sage shrubs, chard, spinach and kales, strawberries & creeping thyme.  This is just an example of a way to incorporate companion planting on a slightly larger scale. Think of forests and woods. No one is there to weed or plant singular crops in a row. Everything is mixed and it thrives all the more for it.

Another way of companion planting is a way called “3 sister planting”, indigenous of Northern America did this long before colonisers arrived. It’s planting corn (upright), beans (climbers) and pumpkin/squash (ground cover). The corn provides support for the beans, the beans fix nitrogen in the soil, the pumpkin provides shade and ground cover to retain moisture. They all take different things from the ground and you get more produce from a smaller ground space whilst also minimising the need to weed, feed & water.

I grow like this in my garden and I love the abundance of green and edibles it provides, plus seeing pops of colour from various flowers amongst my vegetables is something that just fills me with joy, every time I see it. Would you consider using companion planting as any described above?


Benefits of companion planting

Having your growing space looking amazing (in my opinion) with lots of colour and textures and various heights, not only brings back localised eco systems but also better yields of your crops.

Rather than neat little rows, this also has beauty in it but it isn’t natural when you think about it – this was designed to have an easy way of sowing, growing and harvesting. With this method though, it also brought new problems with it. Due to these ‘mono cultures’ (so called as it is a single crop of one thing with not a single other plant in sight), crops are more prone to disease and pests. This in turn meant the rise of pesticides and fungicides to treat things that would not, or at least massively reduced, occur in polycultures. Systems where various crops coexist, give better yield, reduce the sensitivity to disease and lessen pests by attracting beneficial insects and predators, which in turn benefit the plants in pollination giving us more yield in produce.

So, in a nutshell, companion planting means;

  • it prevents disease
  • repels pests
  • speeds up growth
  • efficient use of space
  • good for pollinators
  • looks good

Let’s get into these point a bit more below.


Disease & pests

1.  Prevents disease

Plants of the allium family like onions and garlic have micro organisms on their root systems that release an antibiotic substance that can reduce the risk of disease in the cucurbits (cucumbers, pumpkins, squash, melons etc) and solanaceae/nightshade family (tomatoes, potatoes, aubergine and various of the capsicum family like chillies and peppers). As well as working their magic underground their scent repels the dredded carrot fly. In return, the smell of carrots deters the onion fly. Making these two a well known growing buddy.

2. Repels pests

Plants have developed a defence mechanism in order to avoid being prey to insects. Some insects have gained the ability to neutralise the plants defences through stages of evolution, those insects we call pests. However, those pests are tolerant only of their favourite foods. They would deem others ‘dangerous’ by the plant’s smell or colour, purely because they’re not adapted to the defences of that plant. By planting those varieties around their favourite meal, you can confuse insects and keep your plants ‘safe’. Another way you can do pests control is to plant plants that attract their natural predators. Also called beneficial insects, they tend to eat a wide variety of pests. Whether its where those would love to live or eat the pollen from, having them near means the insects you don’t want get eaten by those you do want. Other things you can do is making sure your growing space is attractive to various other predators, such like frogs, toads, newts, bats, birds, hedgehogs, slow worms. The list could be endless! By planting things like red leaf lettuce next to a cabbage, you cancel out aphids and cabbage white butterflies. The butterflies & moths dislike the smell & colour of the red lettuce and aphids dislike the smell of cabbage, win-win! (I am yet to try this)


Growth benefits

3.  Speeds up growth

Give your plants an appropriate amount of stress to get positive results. When different types of vegetables are grown near each other, plants can grow taller than usual or you can increase the size of your harvest. Plant roots and the mycorrhizal fungal network that grows around healthy plants will enhance the other’s growth. Making it easier for roots to absorb water and air as well as nutrient uptake from the soil. As companion planting gives an small level of stress to the plants, they sometimes grow more flowers, stronger against climate changes – something we’re all experiencing now, or pests. Various plants from the legume family (like beans, peas, clover & peanuts) create little root nodules that trap nitrogen and when the plant dies off, that get released to the soil, enriching it for others. Other benefits are that basil helps tomatoes to go sweeter and not more watery because they use a good amount of water themselves 🍅🌱

4. Efficient use of space

Efficient use of space is one of the biggest advantages of companion planting. If the plants grow well together, you can grow them in the same space. You can grow another type of plant using the open bits of space in a planter of bed. This is especially useful for growing in places where space is limited like a kitchen garden. To give you an example; I grow tomatoes, basil, nasturtium and calendula together in one bed. Maximising space, utilising different root systems and using plants as trap crops for pests, others to enhance flavour and yield. Sadly, I currently have an aphid infestation in my greenhouse and rather than spraying everything with soaps or chemicals I’m letting nature take its course. I’ve actually started to spot ladybirds. Little carnivores to the rescue! 🐞


3 sisters

One of my favourite ways to companion planting is the three sister method – I briefly mentioned this at the beginning of this post. The Three Sisters are the three main agricultural crops of various Indigenous peoples of North America: squash, maize (“corn”), and climbing beans. The maize and beans are often planted together in mounds formed by hilling soil around the base of the plants, squash is typically planted between the mounds. The cornstalk serves as a trellis for climbing beans, the beans fix nitrogen in their root nodules and stabilize the maize in high winds, and the wide leaves of the squash plant shade the ground, keeping the soil moist and helping prevent the establishment of weeds.

The way I’m doing it this year kind of means that I don’t really have to worry about any maintenance on the plants in the way of clearing anything. The corn I’m growing is popping corn (or for use as flour) and does best when it can dry and cure on the stalks. The beans I’m growing that are wrapping themselves around the corn stalks are also to dry and cure on the vine. The pumpkins I’m growing as ground cover will have the plants die off when the squash are ready to harvest. It truly is an ingenious way of growing crops as you’re maximising space, get an abundance in harvest and all plants help each other out with growing and taking up nutrition.

A bit more about this. Pumpkins can be harvested soon after harvesting corn, as they have similar growing periods. Both pumpkins & corn grow well on the same furrow. they both require wide spaces for growing. By growing them together, you’re making efficient use of the same space. Pumpkins function as mulch if you don’t have them trained over a structure. These creeping plants cover the ground and by doing so they suppress weeds and help retain moisture levels in the soil as the sun can’t get to the ground to evaporate it. As corn absorbs a certain amount of nutrients, pumpkins will not get a nutrient overload, which in turn means they won’t go rampant. This means more energy goes into the growing of fruits. As for the third sister, the humble legume (this can be anything from low growing edamame to climbing green beans to vining dry beans), will enrich the soil using root nodule bacteria, it captures nitrogen in the atmosphere and enrich the soil nearby aiding the growth on the corn. The beans will grow the vines onto and round the corn, using the corn as support as well as giving the corn a better hold in the ground. The beans I’m growing are ones that need drying on the vine, ready for storage over winter. By planting legumes and corn together you develop a network of mycorrhizal bacteria as that is attracted to both bean and corn. Through this network of fungi the corn and beans are able to share nutrients and therefore aid each other’s growth.

So, would you consider using companion planting as any described above?
I am definitely not telling you to do it this way, I’m merely trying to make you rethink old systems that are damaging to the planet and everything that lives on it, and to give a more natural way a go. After all, ancient forests aren’t neatly planted rows, but more a mix of plants, shrubs and trees coexisting happily together.