Companion Planting: Part 2 – Up, Out, or Down
For Part 2 of Companion Planting we’ll break down my personal intercropping mantra “Up, Out, or Down” and how it can help guide your garden layout. We’ll also explore classic plant pairings that you can try out in your garden this Spring.
Remember, with companion planting the sum of the parts is greater than the whole.
You can grow healthier, happier plants if you give them good friends. The purpose of companion planting is to grow heartier plants, increase your yield, and improve your soil composition at the same time. A successful companion planter can reduce or eliminate the use of pesticides and fertilizers while enjoying a more robust harvest.
Up, Out, or Down:
- There are plenty of things to consider when pairing plants:
- Water requirements
- Sunlight requirements
- Space requirements
- Soil composition
- Soil nutrients
- Common pests / insects
The shortcut is to simply consider how much space the fully grown plant will occupy and it what direction it will grow. Typically plants either grow up away from the soil (tomatoes, cucumbers, pole beans, corn,) out along the ground (squash, melons, cabbages, broccoli,) or down into the earth (beets, carrots, parsnips, radishes.) You can use these traits to your advantage to grow plants that complement each other and save space.
The absolute best example of this approach is tomatoes (up!), cabbage (out!), and carrots (down!) Properly cared for tomatoes will act like vines, growing up tomato cages or trellises away from the ground. Cabbage on the other hand grows outward requiring a 10-14 inch diameter to fully mature. Carrots take up very little above ground space with the bulk of their biomass growing straight down.
Not only does this holy trinity make optimal use of garden space, the plants help each other as they grow. Carrot greens are delicate and will suffer from too much sun which is totally ok since tomatoes provide shade while also giving off solanine, a natural insect deterrent which helps protect cabbages. In return carrots break up the soil as they grow making it easier for the tomato and cabbage roots to develop. Many gardeners will insist that the flavors of each will be enhanced if grown together.
Tomatoes go up, lettuces out, and carrots down. Pretty simple trick.
Some plants support each other while other pairings inhibit growth. It’s important to research all potential pairings before you plant since some of these negative relationships aren’t obvious.
For example, pole beans like most legumes thrive in poor soil, grow tall and bushy, and create a lot of shade. Beets on the other hand require rich soil and plenty of sun so it’s best to keep them separate.
Cabbage + Dill:
Cabbage helps support the floppy Dill branches while the herb attract wasps which control cabbage worm and other pests.
Carrots + Radishes:
Alternating rows of carrots and radishes are a wonderful combination. The fast growing radishes shade the more delicate, slower growing carrot seedlings. By the time the radishes are ready for picking (2-3 weeks!) the young carrots are self-sufficient.
Tomato + Basil:
Yes, if it tastes good together generally it grows good together. These homies thrive in similar soil pH while the basil’s fragrance deters insects. Basically it’s a pizza waiting to happen.
Nasturtium + Cucumber:
As a rule nasturtiums are great addition to a vegetable garden as they repel most hungry insects but they thrive under cucumbers.
Calendula + Broccoli:
Like nasturtiums, calendulas make fantastic decoy plants for predatory bugs. In particular they attract aphids away from brassicas (cabbages, kale, cauliflower, and especially broccoli.)
This is just a taste, there are hundreds of companions to learn about and experiment with. You’ll have more success as a gardener right out of the gate if you cross reference compatibility before you put seeds down. You’ve got a whole lifetime of garden discovery ahead of you.
Oh! And here’s an amazing tool you can use to generate a gardening cheat sheet based on where and how you’re gardening. Check it out!