Companion Planting - Myth or Fact

Is companion planting based on fact or is it a myth? There is a lot of discussion on the Interweb concerning that very question. More importantly for us is the question, "Do we need to be concerned about companion planting in our SFG boxes?"

I plant marigolds in my SFG boxes because I read that they are beneficial in keeping some insects away from the veggies. Some people plant corn and pole beans together in their gardens so that the beans can use the corn as a trellis.

I have a chart that shows for each crop what things are compatible with it and what are not. For example, for beans is says cucumbers, lettuce and peas are compatible (among other things). It also says that onion, beets and kohlrabi are not compatible with beans.  Does that mean that I should avoid planting a square of bush beans next to a square of onions or beets in my SFG box?

I like to think of my SFG boxes as a mosaic of different crops. I rarely plant the same crop in adjacent squares except along the trellis. Compatibility planting could get complicated when you consider that an inside square is surrounded by eight other squares. Does it really matter if I have a single square of beans right next to a single square of beets? Somehow, I think not. Am I right or wrong?

Then of course there is the question of crop rotation but that is for another time.

Excellent question, TD, always wondered that. Science of folklore? I think some plants are truly incompatible, like they emit substances that hamper certain other plants. But in a SFG?

Interesting that you brought this up. I don't normally go out of my way to think about it but just this morning I pulled out the book "Carrots Love Tomatoes". Since I'm turning under 4 sqs of mustard spinach instead of pulling it out, I wanted to be sure the pole beans I'm planting there next won't mind. I had already switched their trellis spot in my plan when I saw that beans and beets weren't compatible.

I don't think it really matters with SFG but if it's in my face and I can change things around then may as well. If I read something and don't have the space to change it then I don't worry about.

CC

The substances plants emit that hamper other plants are called allelopathic compounds. Walnut trees in particular are known for this. These compounds are real, and they exist -- BUT not all of the companion/enemy relationships mentioned on the internet or in older texts are backed by growth studies.  From my quick reading, results from the "sensitive crystallization method" used in the 1930's matched some known interactions, and additional results using this method were extrapolated to indicate beneficial/negative relationships between other plants. Somewhere along the way these hypothesized relationships were passed along as fact without any growth studies having been done to back them up. Skipping the "test the hypothesis" part means it's not science.

"Is companion planting based on fact or is it a myth?"
  Yes --both. Some relationships are backed by growth studies, others aren't.
   
"Do we need to be concerned about companion planting in our SFG boxes?"
My opinion is no. The benefits a plant provides are available through out the box, and the negatives aren't significant from/to most plants. The "List of Companion plants" on wikipedia gives references - I'd give credence to the ones that give a reference to a somewhat recent journal article with a title so that you can see a study was done. 'Citation needed' or those referencing older books - who knows - you may as well flip a coin. References citing cooperative extensions, you'd probably have to go to the extension page and see if it has references going to a somewhat recent journal article. Dill and fennel are the ones I personally want to research more.

I'd say most the of plants we put in SFGs don't have negative allelochemicals that are particularly influential on each other. They have an effect, sure, but I don't think it's one we'd notice at our gardening scale. Maybe your bush bean plants grow an inch shorter, or your beets are a 1/4" less in diameter, or you get a handful less of cherry tomatoes. For a large grower, all those 1/4" diameter bigger beets would add up to a significantly heavier harvest, for home gardeners - not really. It's not worth trying to drive yourself crazy over, SFG'ing is supposed to be fun and easy!

The positives of companion planting are more indirect than plant to plant -- such as attracting beneficial insects (pollinators, predators), and interacting with fungi (allelochemicals can be both anti-fungal or supportive of helpful fungi). I'd say those benefits outweigh the negatives.

That said, my planning took some companion planting into account, but that's because I LOVE puzzles. Also, additional 'rules,' even if arbitrary, help me get over being overwhelmed by the 'infinite' possibilities of how I could plant things.

I have no idea what's with the [/size][size=undefined] stuff (that's size undefined stuff in square brackets, just in case it doesn't show...) They don't obscure content. I don't know how they got there, they don't show in my preview, and as such I can't figure out how to remove them.

Note: I removed them. Sanderson

My experience with companion planting has been that most of what is written is bunk.  More important is how much space or nutrients are available for neighbors.  So that becomes especially important when trying to mosaic squares and plant each with the amount prescribed in SFG.  If your broccoli variety is at all rambunctious it will crowd out anything but broccoli, kale, or brussel sprouts around it.

I have no luck planting carrots or basil under tomatoes but lettuce does fine.

BeetlesPerSqFt wrote: I have no idea what's with the [/size][size=undefined] stuff (that's size undefined stuff in square brackets, just in case it doesn't show...) They don't obscure content. I don't know how they got there, they don't show in my preview, and as such I can't figure out how to remove them.

I wondered what that meant! Lol

Turan wrote:My experience with companion planting has been that most of what is written is bunk.  More important is how much space or nutrients are available for neighbors.  So that becomes especially important when trying to mosaic squares and plant each with the amount prescribed in SFG.  If your broccoli variety is at all rambunctious it will crowd out anything but broccoli, kale, or brussel sprouts around it.

I have no luck planting carrots or basil under tomatoes but lettuce does fine.

Well put, BPSF & Turan, I agree. Most of it is folklore, absent the scientific method. And a lot of trial and error.....

I have been giving this a lot of thought this year. I am planting things a little closer than normal, more out of curiosity and experimentation than anything else. I have seen some gardens where things seem right on top of each other, I am a firm believer that good soil, adequate sunlight, and appropriate amounts of water are the key to this wonderful endeavor.
     So now my thinking is making sure the plants are not shaded by other plants, In this thought, I grow mega amounts of garlic (hey Sanderson- I miss Gilroy) which I always plant in the fall. I made strip garden which is about a 4' wide flat area on the side of a hill. Last fall I planted garlic right down the middle of it. I am going to plant beets on both sides, the garlic will be much taller by the time the beets start to sprout, so sunlight shouldn't be a problem. On the north side of this strip, I will plant cucumbers and green beans.  I am going to plant a potato at each end just for giggles. I have been building this soil for a few years, so it should be fun to see what happens. 
     In a 3 X 5 garden I have two rows of beets, a row of lettuce (which hasn't sprouted yet  , and the beets aren't doing all that well either. I need to be patient. I will be putting a row of beans on the north side, a zuc on one end corner, and a crook neck on the other end corner. I am going to put a few cherry tomato plants in this on too.
     I have read a lot about companion planting, and I am keeping my eyes wide open about what they all say, but, I want some practical experience for myself. We'll see.
Rock

Good plan, Rock.

One simple, and very old, companion planting is The Three Sisters which originated with the Iroquois.  Corn, Beans and Squash.  Corn:  A natural pole for beans to climb - Beans:  Fix nitrogen and stabilize corn - Squash:  Shallow rooted, it keeps the soil moist acting as a sort of living mulch, and also the spines of the squash can help discourage critters.

I will admit that I've never tried this, but it's probably one of the oldest theories out there.

There are several threads on peoples experiences with Three Sisters gardens.  It was almost a fad here a couple years ago.

Here is one thread https://squarefoot.forumotion.com/t7757p100-three-sisters-thursday?highlight=three+sisters

I have read about the Three Sisters, they found something that worked and ran with it. I like how it works, but I have a problem that messes me up when it comes to this. I don't know why, but when it comes to Brussel Sprouts, Corn, Strawberries, Okra, and Morning Glories, they don't grow for me. Especially corn. They say here in New Hampster (New Hampshire) that corn should be knee high by Forth of July, yeah right, I am lucky if it gets knee high by September. The only ears I see are on the animals that come just to laugh at my miniature corn stalks. It pretty sad when they are rolling on the ground, pointing at the mini stalks and laughing at me.
     But, being kinda handy, I make custom Trellis for what ever I can grow. Now I am just growing things closer together.  Rock

OK, Rock, your corn won't grow? Corn does nothing else but .....grow. Usually. I mean, are you putting it in ground, or MM? I have never not been able to grow corn. In my opinion however it isn't worth the square footage in my SFG, but I did it one year. Country Gentleman was the variety. Delicious. Weird, kernels were not in rows! Also grew silver queen. Early. Tender.

When I lived in California, (not far from Sanderson) I had corn coming out of my ears (pun intended), Okra was the best, and strawberries bigger than golf balls. But here, I am ashamed. I just hang my head and try to change the subject, embarrassing. I wish I could get Morning Glories to to vine like they did in California, but out here I get maybe three or four feet and some flowers. I don't even try anymore, I can grow beans, cucs, and other things that make me happy. Rock

Yeah, Morning glories only get to be about 4 or 5 feet tall, but they flower like crazy! Lots of corn at the farmer's markets anyways!

Rock, Strawberries the size of golf balls!  One would think CA strawberries came from Texas.    

I have a 1' x 3' box in an area I call the "no-grow" zone.  I raised some MG last year and planted them in that spot since it already had a trellis and they thrived.  Here are volunteers this spring.

bigdogrock wrote:When I lived in California, (not far from Sanderson) I had corn coming out of my ears (pun intended), Okra was the best, and strawberries bigger than golf balls. But here, I am ashamed. I just hang my head and try to change the subject, embarrassing. I wish I could get Morning Glories to to vine like they did in California, but out here I get maybe three or four feet and some flowers. I don't even try anymore, I can grow beans, cucs, and other things that make me happy. Rock

Sigh... Bigdogrock, Sanderson...   I can't get a morning glory worth beans to grow here in my red clay.  Back home in Los Angeles (I don't think I'll ever stop referring to it as home), Four o'Clocks grew like weeds.  Here...  I've not been able to get one to grow.  I keep trying every year though.  I just bought some new seeds from Park Seeds...  here we go...

Windmere, mine are in a box with plywood bottom, set on bricks and filled with Mel's Mix. Maybe you could try that or top the clay with a thick layer of MM. ?? In CA, they are almost an invasive weed!

Windmere - this pic is just for you.  Planted in spring 2015 from purchased seed.  One group is planted in Potting Mix and the other group is planted in MM.  They died back and just sprang up thru the mulch this spring.  The plant in the first picture is about one and a half feet tall.  They are not fancy varieties.  Some are red, some are white and some are yellow.

Yolos:

Aahhhrrrggg....   

Hey Windmere, I know what you mean about Morning Glories growing like weeds. They used to cover an entire six foot tall fence and climb the power poles and crawl across the lines. They were beautiful and the birds liked them. I miss that. It seemed like the longer the vines got the deeper the colors were. I don't have any pictures, (that was the pre-cell phone era, now the "old man" jokes hit ) but my memory of it is cool.
     I am sure that growing them here in New Hampster (New Hampshire) is different from Central California, the latitude, soil, temps, and length of growing season all play into it. But, having said that, when I see some folks that can grow them to be 10+ feet high, I wonder how it works for them and not for me . 
     In California, there were so many favorable conditions for growing that I had so much success by throwing seeds into the ground, the key was watering. Here in New Hampster (New Hampshire) it is almost opposite. The soil is not very good at all in most places. There are a few spots where things do grow well, but those places usually have had soil amended or added. I have spent most of my energy building the soil. I have eight compost piles, all in different stages of decay. or different stages of nutrients. 
     I use a grass catcher on my riding mower (whose name is "Wild Thing" just for future reference) and put all the clippings into the piles. I also take a lot of time in the fall to mow the leaves into rows, which chop them up then vac them up and add them to the piles and TRY to mix them some what, but that task is just to big to do by hand. I end up letting them decay and then try to add them all together before winter, add some chicken manure and water and watch the pile cook down. If I only had a tractor .
     That is why SFG works so well here. Anyway, I will keep trying to grow the MG, and one day I might even try corn again, but with a farm right down the road that is acres and acres of corn, I will wait till it is at the local market and buy it. Thank you for your input about this, Rock

P.S.- I just had an idea, the next time I see some Morning Glories that are doing well I am going to ask about where and what kind of seeds, and what they do for the soil, and if they fertilize, etc. Rock

Last year I grew morning glories in Mel's mix and outside of it. They were great. I actually carefully harvested the first seeds to show up not realizing that all those flowers made multiple seeds that drop everywhere at the end of the season. I'm just waiting to start pulling them as they try to grow again this year as it's not part of the plan. Rock, if you want some seeds PM me your address. I'll be happy to send them.

CC

Thanks!

Looks like Mel had companion planting ideas, too. I was just reading his book 'High-Value Veggies' and in the section on kale he says it will do well next to beets, herbs, onions and potatoes but not beans, strawberries and tomatoes. Then under broccoli he says beets, onions, garlic and cauliflower are natural companions to broccoli.

So there you have it, sports fans.
CC