Thoughts on Companion Planting
Beautiful voluptuous mustard with flowering companions, as pictured in ‘Edible Landscaping’ by Rosalind Creasy.
Many gardeners, both new and seasoned, are intrigued by the concept of Companion Planting. Our bookshelves are home to dozens of books on the subject. Most of them are filled with nothing more than nonsensical old tropes. Carrots do NOT love tomatoes! But some of these books do have inspiring photos and illustrations and even recipes. Aesthetically, ‘Soil Mates' by Sara Alway is among my favorites, although it is certainly one of the worst with regard to the highly oversimplified information presented. Some of the more offensive suggestions include planting peppers with spinach, as well as cabbage with peppermint! How my heart goes out to anyone that has actually planted peppermint in their kitchen garden. And how I wish someone with actual gardening experience had written this charming little book. No offense intended to Ms. Alway, who is obviously a clever writer guilty only of referencing previous publications.
Companion Planting is not only a modern phenomenon. It has been practiced and documented for thousands of years in many different cultures around the world. But in the more recent history of Companion Planting there are two distinct tracts:
The first is that of French Intensive Vegetable Gardening, or La Culture Maraîchère, a centuries-old method that is primarily concerned with intercropping for the purpose of continuous production and high yields relative to the space available. Soil fertility is key to making this practice successful. French Intensive Vegetable Gardening has informed much of contemporary Urban Agriculture and Market Gardening.
The second is that of Biodynamic Agriculture. In 1924, Rudolf Steinar presented his vision for an agriculture that utilized the symbiotic and replenishing relationships in nature as an alternative to the synthetic and exhaustive industrial agriculture that had become common in Europe by that time. His ideas reflected diverse ancient practices and beliefs, including some that we now regard as “occult". But these lectures were the advent of what we know as Organic Gardening. They have also informed some aspects of Permaculture.
It is at the intersection of these tracts that we find the modern iteration of Companion Planting. It is a juxtaposition of historic cultural practices and superstition. Which is not to say that Biodynamic principles are mere mystical woo, because they are not, but much of the early literature produced by the movement is regarded as gospel in spite of being poorly researched. In fact, many of the suggestions in modern Companion Planting books are based on the observations of one man in just one garden in Chester, New York, first published in a pamphlet in 1943 by the Bio-Dynamic Farming and Gardening Association. That information was amended using classical horticultural references by Helen Philbrick and republished as a book called ‘Companion Planting' in 1966. I have a copy of that first edition, and it is indeed a book that I cherish, but the quality of the entries varies wildly, and it is clear that there was little understanding at the time of how exactly to manifest these ideas in the garden. In the postscript the author acknowledges as much. Some of the fallacies presented in this beloved little book unfortunately persist in modern Biodynamic literature.
The original book on Companion Planting, compiled by Helen Philbrick and published in 1966. It includes an entry for Nettles that is still relevant today. Use of Nettles as a fertilizer and an activator for compost is one of the most easily employed and impactful of Biodynamic principles.
Of course, we should all know by now that plants are intelligent creatures fully capable of competing and communicating with neighboring species. The idea that certain species will benefit or supress others is not far-fetched at all. There are hundreds of peer-reviewed studies available online that attest to the potential of Companion Planting to mitigate pest populations, to enhance pollination, to improve disease-resistance, and to suppress weeds. The research is primarily pursued on behalf of commercial growers, but the conclusions make clear that plants, like us, benefit from being part of a diverse community of creatures. Which brings me to the most important point that anyone can make about the subject of Companion Planting:
BIODIVERSITY IS KING.
There is no precedent in nature for whole fields of a single species. This arrangement exists solely for the presumed benefit of humans. But monoculture ultimately leads to depletion of the soil and the necessity for ever more inputs to help mitigate the loss of fertility as well as pests and disease. It is not sustainable. It has likely contributed to the collapse of myriad civilizations since the dawn of agriculture. There is no doubt that it is hastening the decline of ours.
Even in the context of a garden, limiting species to just a few annual vegetables in tidy weedless rows divided by bare soil can have disastrous consequences, especially over the course of several years. Every hardware store and garden center stocked with herbicides and pesticides and fertilizers is a testament to the sad state of our gardens.
Obviously we all have to start somewhere. This is not meant to be a critique of your gardening practices. We still buy bags of kelp meal, fish bone meal and azomite every few years. Composting is a skill that we are still learning, so we add locally-produced compost to our most demanding beds every year. But our gardens, modest though they may be, produce tons of food and seeds without the need for any other intervention. Pesticides and herbicides are utterly unnecessary.
The garden is an ecosystem. Biologically diverse ecosystems are rarely vulnerable to the ravages of pestilence and disease. Whenever you clear a patch of Earth you risk the loss of valuable topsoil and its microscopic inhabitants. You also invite dormant seeds to germinate, as well as the intrusion of opportunistic pioneer species. To mitigate these potentialities, cover every inch of bare soil with plants or mulch. The more plant species you can include, the better. Consider a living mulch of red clover and blue fenugreek. Create an ecosystem. Shaded soils maintain moisture and healthy populations of bacteria and fungi. Flowering plants attract diverse community of insects. All of these creatures contribute to effective pest and disease management. And if you honestly don't think that bare dry soil is an issue worth fussing over, I suggest watching Ken Burns documentary ‘The Dust Bowl', and reading the excellent ‘Teaming with...' trilogy of books by Jeff Lowenfels. It may change your perspective.
Once you're convinced that a diverse selection of plants will benefit your garden, you want to know what plants to plant and what to plant them with. You are vulnerable to suggestion. And I suggest that you first sit down and determine what it is that YOU want. Plant what you would like to eat. Plant flowers that you'd like to see. Plant herbs that you will use for tea. Consider things like color and fragrance. Check out a dozen garden design books from the library and just look at the pictures. Make note of what combinations you like and why you like them. We are all artists, and the garden is a canvas on which we can paint with color and texture. Ignore the imposition of arbitrary rules. Venture outside the lines.
Also, I suggest that you avoid every book on the subject of Companion Planting. They are confusing and too often just plain wrong in their assertions. For example, one popular book entitled ‘Companion Planting' states, among other ridiculous things: “Although you could follow a broccoli crop with a cabbage crop successfully, you couldn't follow it with cauliflowers." Really now. These plants are all morphological variations of the same species. And following ANY Brassica crop with another Brassica crop is never advised. Not every family of plants benefits from rotation, but Brassica definitely does. Which speaks to the utility of beds rather than rows, but that is a topic for another day. The point is that this book is full of terrible advice. It’s the mint-in-the-cabbage-patch all over again. And the majority of books about Companion Planting are no better.
Of course, we do have to consider the cultural requirements of our garden occupants. It would be unwise to pair lavender with strawberries for example. Believe me. I know. I have tried. These plants simply have different needs. The hot rocky soils in which lavender thrives will see strawberry plants wither and die. Strawberries like rich shaded soils. Better companions for strawberries include chives and other perennial onions. But chives are especially good. Throughout the year, the fragrant chives deter a broad spectrum of pests and critters. In June, the chive flowers attract pollinators that improve fruit production. And in winter the decomposing chives insulate strawberry crowns and nourish the soil. Beds of strawberries and chives can produce for many years with almost no attention at all. They are truly ideal companions.
There are other mutually beneficial combinations illuminated and illustrated throughout garden literature. Nasturtiums and leeks is one. Tall corn adorned with pole beans is another. These are classic companions, and their relationships are easy to understand. Nasturtiums effectively shade the soil around leeks, maintaining moisture and providing shelter for beneficial beetles and spiders and snakes. Corn provides support for climbing beans and benefits from their nitrogen-fixing roots. More recent literature extols the value of basil and marigold as companions for tomatoes, and indeed the limonene exuded by some selections of basil and marigold does deter whitefly, which is especially helpful in greenhouse culture.
In the realm of Biodynamics, there are several plants that are considered “beneficial" to other plants in ways that are not necessarily easy to understand. On the contrary, the suggestion that yarrow, comfrey and nettles be grown anywhere in the kitchen garden seems quite absurd. Because it is. They are indeed beneficial, almost magically so, but not as companions for garden vegetables. These profoundly medicinal plants are useful as nourishing mulches and fertilizers. By all means, grow them! But not in the kitchen garden. They are vigorous and hardy perennial spreaders. If you'd like to grow similarly nourishing plants in the kitchen garden, consider diminutive Roman Chamomile, which makes a fragrant living mulch, and beautiful Lychnis viscaria, an obscure little wildflower that is rich in unique brassinosteroids.
But will calamity ensue if you sow bush beans next to your onions, as nearly every resource on Companion Planting indicates? No! We do it on the regular, because it makes sense to us. Onions are transplanted in early spring. Between rows of those transplants we sow lettuce seeds. Come early June the lettuce is harvested and the onion tops are nice and tall and it is time to sow beans. Why not tuck the beans between the rows of onions? Companion Planting suggests that onions inhibit the production of beans, although we have never observed this to be the case. The only garden calamities we have encountered have to do with climate and culture and critters. Never has a tomato abutting a cucumber resulted in chaos. But I could write several volumes on why deer make poor companions for gardens.
Gardening is not unlike sex, in that you can really only learn by doing. Mistakes will be made. But understanding how it works and discovering what you like can only be achieved by trying new things. Don't let some random book choose your companions for you. Do, however, let books inspire you.
We have written previously about our love of the ‘Edible Landscaping' series by Rosalind Creasy, and these books are still among our absolute favorites. In any one of these books you will find fantastic photographs of a wide variety of garden styles and plant combinations, plus information on the cultural requirements of those plants, and even recipes! We love recipes. What you want to eat should influence your garden perhaps more than anything else. The ‘Edible Landscaping' books advise with this truth in mind, but unlike so many other books they do not neglect the potential beauty of a kitchen garden. ‘Edible Landscaping' marries the aesthetic and the functional in ways that no other book has.
’The Romantic Herb Garden' by Caroline Holmes is an excellent and underrated book filled beautiful photos of gardens and much more information and ideas than the title would suggest. The focus is on “herbs" in the most broad sense of the word, often as companions and and as ornamentals. Growers that want to integrate more culinary and medicinal herbs into their kitchen or perennial gardens will appreciate this book, as will designers seeking to start from scratch. Though out of print, this book can be probably be found used.
Throughout our website we repeatedly harp on the importance of incorporating flowers into vegetable gardens. The revelation that comes with finally adding a diverse selection of flowers to a vegetable garden is a profound one. Flower farmer Lisa Mason Ziegler wrote about this phenomenon in her book ‘Vegetables Love Flowers'. As you might expect, the focus is mainly on flowers, but this beautiful tome might be exactly what a stubborn by-the-book vegetable gardener needs to coax them out of their comfort zone. The photos are stunning, and the cultural and cutting guides for the flowers are fantastic.
Sally Jean Cunningham is a vegetable gardener that gets it. Like us, she has been down the Companion Planting path and come to similar conclusions. If you buy only one book on contemporary vegetable gardening, ‘Great Garden Companions' would be a worthwhile choice. Though it has very few photographs, it is filled with charming illustrations and tons of valuable information presented with clarity and concision. Though we cannot commend every suggestion presented (in part because we detest the raised bed craze), it is among the most exhaustive books on the subject of a healthy biodiverse kitchen garden.
As a final suggestion, just remember that a garden is a garden. What goes into the garden should be based on the soil, the site, and most importantly, the preferences of the gardener. Plant everything. Perennials, vegetables, whatever you want, all in the same spot. Learn the hard way. Consider sun, consider water, but do not waste precious planning time worried about whether your cucumber harvest will be thwarted by some nearby dill. Always include flowers and please mulch. Welcome imperfection.
