I often get asked the question, "What is the difference between companion planting and interplanting," and rightfully so! The terms Companion Planting and Interplanting are often confused because they are so similar in nature and practice.
Both are useful in the garden and when applied appropriately, can improve the health and vitality of your plants, provide beauty and texture, improve pollination, and reduce the pest burden.
Additionally, both practices involve growing one variety of plant among plants of another variety.
Where people get confused is understanding their relationship to one another.
When I'm trying to define these two terms to clients, I liken their relationship to plums and prunes....
You might be familiar with the saying, "Not all plums are prunes, but all prunes are plums." Well, it's the same story with companion planting and interplanting.
Not all interplantings are considered companion plantings; but all companion plantings ARE interplantings!
So, they're essentially the same thing except that Interplanting is an "umbrella" term that encompasses multiple different planting practices, including Companion Planting, Succession Sowing and Crop Rotation (see my Intensive Gardening post for more on the topic of succession sowing and crop rotation).
An example of interplanting that I'm using in my garden this year is with arugula, spinach, mustards, and Brussel sprouts.
I know that arugula and spinach have a tendency to bolt once the weather warms up in late May. In order to avoid this (or at least slow it down), I've interplanted these smaller plants on the northern side of my much taller mustards to provide shade.
I've also interplanted Brussel sprouts down the middle of the same row because as they mature, I'll have harvested the mustards, spinach and arugula, opening up space for the Brussels to fill out.
I could've just planted the Brussels in their own row, but I'm maximizing that space by interplanting small, quicker-to-mature crops alongside larger, slower-to-mature crops. That is a mainstay principle with interplanting!
Other examples include combining plants with deep roots, like tomatoes, with shallow rooted plants, like lettuces, to avoid competition for soil space.
Plants that require pollination, like squash, melons and cucumbers, may be grown with flowers that attract pollinators.
Tall plants like corn can provide support for vining plants like pole beans, while tomatoes can provide shade for sun-sensitive crops like lettuce.
Intensively Planting crops and flowers close together will also help suppress weed growth in the garden.
Ultimately, the benefits of interplanting will vary depending on the chosen method. So, let's look at how interplanting works within the scope of Companion Planting.
Companion Planting falls under the Interplanting Umbrella but is more specific in its practice and in its goals.
Generally speaking, INTERPLANTING is growing two or more plants in the same garden space with the goal of maximizing space, producing a higher yield in a smaller area, increasing color and texture, and improving the health of your plants.
COMPANION PLANTING accomplishes these overarching goals by combining two or more plants in the same space with the goal of using their synergistic relationship to enhance growth, protect plants from specific pests, create a haven for beneficial insects, and encourage pollination.
So again... not all plums are prunes (but all prunes are plums), and not all interplantings are companion plantings (but all companion plantings ARE interplantings!)
An example of companion planting in my garden this year is interplanting brassicas (specifically cabbage, cauliflower, & kale) with plants in the allium family (onions, chives, leeks, and garlic), as well as aromatic herbs such as dill, mint, rosemary and oregano.
Brassicas are particularly vulnerable to damage from caterpillars, specifically the cabbage moth/worm. These pests locate brassicas by the scent they release (as is the case with most pests).
However, you can deter these pests by confusing them with a nearby companion plant that releases a stronger scent. A perfect example of this are alliums and aromatic herbs! Their scent overpowers the scent of the brassicas, throwing off and repelling the pest.
OTHER EXAMPLES INCLUDE:
AND THERE ARE SO MANY MORE EXAMPLES!!!
** Note ** Many of these examples are from my FAVORITE companion planting book,
➡️ Keep in mind that the various interplanting techniques may overlap, so don't let yourself get caught in the weeds of all the terminology!
There are so many wonderful ways you can pair plants, but you can easily get overwhelmed by the pairings and then not plant anything at all. Don't do this!
I remember back in the day drawing out very detailed maps of companion plant pairings and driving myself crazy with whether or not I had the best plan laid out.
It wasn't a wasted effort, to be sure, but I also don't believe you have to go to this extreme to reap the benefits of interplanting.
As you dig deeper in the interplanting world, you may come across dogmatic rules of thumb - take them or leave them. Learn from them, but don't be bound by them. What works for one gardener might not work for you (& vice versa), but you'll never know unless you try.
And that's my final piece of advice to you, fellow gardener, JUST GET STARTED AND TRY!
1. Tomato plants interplanted with parsley
2. Pepper plants interplanted with basil
3. Tomatoes with a border of Marigolds
4. Dill interplanted with Cabbage
5. Nasturtiums as "trap plants" for squash bugs & aphids (trap plants will draw away a pest from another plant, so you DON"T actually want to plant them together!) Nasturtiums are one of my favorite plants, by the way!
6. Onions interplanted with lettuce
7. Radishes interplanted with carrots
8. Corn and vining plants, such as winter squash, pumpkins & cucumbers
9. Spinach interplanted with strawberries
10. Bush Beans planted with EVERYTHING!!! (Well, everything BUT onions & fennel - they especially don't like onions!)
NOW GO GET PLANTING!