One benefit of companion planting to authors is that it sells books.

rgreen, maybe you should try my hey whats your zone pickup line.

Lol... okay, I'll have to try that.

Thanks, Nancy!

Dave, see for example exchange of nitrogen between legume and grain

http://books.irri.org/0792317742_content.pdf#page=168

Note that this is mediated by a third organism. Note also that underplanting wheat with clover started around the year 1000 (or before) in Central Europe. Corn, beans and squash as living mulch in the river plains in the Southwest may predate that. At the same time chinese farmers learned of the symbiosis between rice and certain algae, which allowed new crops to complete, year after year, without manure. Some companionships are not new stuff and time tested.

Other examples include combinations of deep rooted and shallow rooted crops, also exchanging nutrients through myc.. Long term advantages can be obtained also by underplanting non-symbiotic plants with symbiotic plants, and also having living roots in the soil at all time (call it "delayed companionship"), which preserves the mycorrhizae and therefore the soil quality. Of course if you till you will never see much of this, but this is where soil science is heading these days. Complex, diverse companionship techniques including above soil and below soil organisms, and soil fertility being dominated by biology, not chemistry.

Above ground, the apparently best proven companion strategy is having flowering plants near crops, as they attract beneficials. Based on my and other experiences, marigold protecting cabbage against the cabbage moth seems to be the most certain. Farmers nowadays plant flowering species at the 1% level in their cover crops, same reason.

Companionship effects due to roots touching one another can not be large. Roots occupy a tiny fraction of the soil volume. Nearly all companionship effects have to be through mycorrhizal networks, as they occupy 10 to 100 times more soil and effectively connect plants.

In fact, if you search around the net for the five principles of healthy soil, you conclude inevitably that you have to have companionship to extract the full fertility potential of your soil.

Note that Louise Riotte, who authored the companion gardening book "Carrots Love Tomatoes" is also well known for writing the book "Astrological Gardening". That may put some things into context here.

I think the question about planting companion plants to attract beneficial or deter harmful insects has to be the extent to which the payoff exceeds the investment. That is, if I have to plant 20% fewer cabbages in order to fit marigolds between them in my garden, and the result of that is 10% less destruction by cabbage moths, it just wasn't worth it. But maybe it is. It will depend on the specific circumstances. If 1% marigolds does the job, more power to them.

I believe the reference you point to as an example of fixed nitrogen transfer specifically states that there is actually little evidence that intercropping of legumes with companion grasses actually results in any fixed nitrogen being transferred from one live plant to another. Seems to still be an open question. The fixed nitrogen is released as the root system of the legumes decompose, which isn't supposed to be happening a lot while the legumes are alive.

"In fact, if you search around the net for the five principles of healthy
soil, you conclude inevitably that you have to have companionship to
extract the full fertility potential of your soil."

Well, I've never
seen that, and I still have not yet seen any real research that would
convince me of it. I don't consider plowing legumes under to release
fixed nitrogen in the interest of soil fertility for a subsequent crop to be
"companionship". It's really more about smart crop rotation. Sorry, but it's handwaving statements about inevitability like
that that put some of us off a bit.

I'm still looking for real commercial examples where farmers plant things together to extract the full fertility potential of their soil in order to improve quality or increase productivity.

Daninthdirt, do you accept the work of Monica Gagliano of the University of Western Australia as a credible source? Proven that peppers germinate faster when in the presence of fennel? Would this be considered companion planting or something else? I don't think we can completely write off companion planting, but think more science around it is needed.

The title of that book should have been "The root canopy of carrots and tomatoes complement each other, and they are both mycorrhizal". Then there would be no misunderstanding, and synergic effects in live soil would be understood. Dan, there is the live mulching effect too, but the real difference is nutrient sharing and extended soil access.

Monica Gagliano's work didn't prove 'that peppers germinate faster when in the presence of fennel.' Fennel inhibited germination in her experiments. The surprise was that germination was faster when fennel was present but screened than when no fennel was present. The conclusions to be drawn from the experiment are still under discussion. Gagliano's work

As to peppers and fennel, if real research shows that one helps the other that would be interesting. When I look up Gagliano's work with pepper and fennel, I see that she found that fennel actually interfered with pepper germination *except* when the fennel was chemically isolated from the peppers. Huh? So she's suggesting some other kind of mysterious communication is going on. Like they hear each other? Other scientists are interested, but no one has confirmed that work. I have to say that it's easy to find companion planting advice/lore that specifically says that fennel should NOT be planted with peppers. So, um, what's the deal? Also, it would be interesting to know if commercial growers germinating peppers actually see the value in fennel, and actually use fennel (but block it off from the peppers!) when they are germinating. If there were a way to improve quality and productivity in this way, commercial growers would be all over it.

As to carrots and tomatoes, did Louise Riotte come up with that because of research she did, or did she read it in the stars? Again, show me a commercial acre of tomatoes that is interplanted with carrots to maximize productivity and quality. If production farmers don't see value in it, why should I? Yes, tomatoes and carrots are both mycorrhizal. But so are most other plant species. All those species welcome mychorrizal fungi into their roots, and benefit from them, but one species isn't really helping the other. The fungi is helping the plants.

floral_uk beat me to it. Yes, the relationship between peppers and fennel really isn't well understood. I like fennel, and I like peppers, but if they like each other, they do so in ways we don't understand.

Well, I suppose it's time to put my joking aside and speak seriously for a moment. Bummer...

Symbiosis exists. This is not disputed. Competition exists. This too is not disputed. In this instance we are discussing the former. The studies are interesting, and unfortunately, have much less influence over gardening methods than do tales of supposed success. In the case of companion planting, while there is evidence (both laboratory, and observational) of plant interaction - and to cut to the chase - there is little evidence of any 'companion effect' having practical application for the home gardener. Even in the case of the Gagliano's work, 'companion' would be the wrong terminology. Rather, in the response to the fennel, the evidence points to competition. There is lots of evidence of plant competition. From juglone, to the elongation of internodes, competition between species is as much a fact as is instances of symbiosis.

What is yet to be proven is if such interactions (of either competition, or symbiosis) affects yields. And... if such increases are ever shown, is it on a small enough scale to make any practical difference what so ever? - especially for the home gardener.

Dan, in the discussion and 'conclusions', the authors of the study hypothesize that the unexplained results could be perhaps better understood if it could be shown that plants could sense magnetic fields.... another topic all its own.

There is no agreement on what was going on here with fennel and peppers. It's research that, as good research does, comes up with other questions. The idea that plants somehow communicate with each other in ways that are not biochemical is astonishing and certainly needs more work. Bottom line is that this work doesn't point to any actionable gardening strategy, either for the commercial grower or the home gardener. Maybe someday it will.

But, rgreen, I think you are exactly right, that this is all somewhat about terminology. The word "companion" suggests friends doing good to friends. But that's not what's going on here. Any advantages that are accrued by planting one plant next to another don't obviously have anything to do with resource sharing. There's nothing in a carrot that a tomato likes. There is nothing in a marigold that a cabbage likes. It would seem that fennel and peppers produce a somewhat bipolar response.

And that was my point about yields. The financial well-being of commercial gardeners depends on quality and yields, and so if companionship among plants was a real factor in quality and yield, they'd be the first to take advantage of it! Are commercial gardeners just dumb? Do they not read all the books about companion gardening? Do they choose to just obstinately ignore that advice, knowing they'll be paying a price?

I take the concept with a large grain of salt. Certainly some plants can interact via allelopathy, but most of the famous examples of that are negative alleopathic effects used in resource competition.

If companion planting means crop diversity, then, yes, there are benefits to having more than one kind of plant in an area, but that could be any combination of plants, not a set 1:1 match. If companion planting means crop rotation, then yes, that's a good strategy (if you can use it) for preventing disease and pest buildups.

And, like most other things in the Almanac, correlations are extremely time/place dependent. They often reflect the anecdotal experience of one person at one time in one place.

Cover crop use has as much to do with keeping your soil from blowing
away and/or running off as it does with replacing/retaining soil N. Hence why many people that use cover crops still end up applying supplemental nutrients via fertilizer. And are cover crops really an example of companion planting? You're not maximizing the production of both crops, just the one.

I don't find the commercial grower argument all that relevant to the discussion - purely from a logistics perspective, commercial growers strongly trend towards monocultures because they have to emphasize efficiency in large-scale agriculture by minimizing labor and mechanizing as much as possible. Monocultures are easier to plant, easier to water/fertilize, easier to harvest on schedule, easier to process. There would have to be a vastly significant benefit of companion planting in order for it to be implemented at that scale. At a smaller scale, though, a home gardener might be more inclined to put in the extra work and reap the smaller, though still significant benefits that might be there.

Good points, aniajs. Let me argue that the commercial use of companion planting would not require dual strategies for harvest or care. It's about ONE crop, but you throw in some seeds for a companion crop while you're at it. In fact, just seed with a mixture of seeds. One-pass seeding. You don't care if that companion grows that well, or even produces much fruit. You don't necessarily even harvest it. Your care is aimed at the primary crop, and the whole purpose of the secondary crop would be to help (somehow) the primary crop.

I have an open mind about this. I'm not biased against planting plants together because they like each other. I just don't see any real evidence for a benefit.

well, it could not be "any combination of plants". If you plant only legumes you are not going to get as much as if you plant a legume, a daikon and a grain. But generally pasture optimization shows higher biomass yields with higher diversity. Even after you have planted your deep rooted species, N-fixing species, high root surface, there are still benefits in having more replicas of the same functionality.

It could be as simple as maximizing total root surface to maximize mycorrhizae population, and maximizing water infiltration due to increased number of channels. There are numerous carryover effects: winter living roots keeping the myc. strong for this year's crop, last year root channels allowing better penetration to this year's crop (there are important advantages in getting deep roots, from more infiltration, more water, colder water to more nutrients to, finally, a proper nutrient cycle). We would not have such a lively discussion if the question was framed as : Is there symbiosis in the garden? Of course, but we know very little about it. Soil science was blocked by chemistry-is-all types for a generation, but it is fairly clear that the dominant effects are biological.

Maximizing total root surface in a volume is simply a matter of planting lots of stuff together. Most plant species encourage mycorrhizae populations in their roots, so it isn't matter of tomatoes liking carrots. In that sense, there are some advantages in planting things densely. Of course, there are lots of disadvantages with planting things densely. If I plant five tomatoes in a six inch pot, we could say they would benefit from shared mycorrhizae, but they sure wouldn't grow that well.

As to legumes and nitrogen fixing, I think we already concluded that there was little evidence that living nitrogen fixing plants actually contributed any fixed nitrogen to other living plants nearby. That was explicit in the link you gave.

But lets get back to "companions", and terminology. That's what the original question was about. The way "companion planting" is advocated is by planting certain varieties of plants with certain other plants. So let's define it the way the advocates define it. Both plants are living and supposed to benefit from each other at the same time. Some plants are supposed to "like" specific other plants living near them. "Carrots love tomatoes". I've seen no evidence of any biochemical benefit from such companion planting.

I agree that we have gotten way off course from companion planting - at least as the label is normally used. It makes no mention of things like biomass optimization, nitrogen fixation, root surface exposure, or symbiotic Mycorrhizae. Those issues may or may not be factors in gardening, but they aren't relevant to the "Companion Planting School of Thought".

And honestly Glib the statement

"In fact, if you search around the net for the five principles of healthy
soil, you conclude inevitably that you have to have companionship to
extract the full fertility potential of your soil."

is so open to debate in so many ways that it would need its own forum to do it justice.

Dave

"Does anyone believe in companion gardening?"

No.

I'm with a few others here that I'm good with some companion gardening, like planting for insects... I plant nasturtiums as a trap plant for aphids, and plant marigolds to attract beneficial insects, that sort of thing.

I don't think that planting stuff together makes anything taste different, unless there is something to the notion that different plants take up different nutes, and that could have an effect on taste. I don't know anything about how nutes and taste work though, so that's a guess. Maybe basil offgassing is supposed to trigger sugar production in tomatoes the way a ripening banana offgassing triggers ripening in some fruits- but I think that's a serious stretch of a guess.

I think there is something to the fact that some plants don't seem to grow as well together as others do- but as has been suggested earlier in this thread, that's more of a knowing enemy planting rather than companion planting. There is also something to following companionship with crop rotation, it's better to be in some orders than others.

Then there is companion gardening like a three sisters garden, and I think that works wonderfully.

Three Sisters is one thing. That's mainly about mechanical support. A great idea. Insect management and pollinator attraction is another. But why do carrots love tomatoes, and why is there is a huge list of which other plants love each other? I mean, several pages of "this goes well with this". Sorry to put it this bluntly, but "companion planting" is a phrase that lots of nonsense seems to hide behind.

And even Three Sisters has its problems since it is so heavily variety-used dependent.

Dave

Whew! I didn't realize how much attention my question would get. I'm more interested in knowing what plant attracts beneficial insects to certain plants and what plants should be planted next to each other. I guess my idea of companionship planting needs to be adjusted.

Well, if you Google "companion planting" you'll get long lists of who likes who and who hates who with absolutely no factual basis presented. If you want to know about "attracting beneficial insects", I'd just Google that and forget about companions.

Thanks, Dan. I guess I always thought there was some truth to it.

In fact I just sent a wrong link. There is plenty of evidence for N transport through myc.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946601/

http://download.springer.com/static/pdf/953/art%253A10.1007%252Fs11427-012-4330-y.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs11427-012-4330-y&token2=exp=1459631984~acl=%2Fstatic%2Fpdf%2F953%2Fart%25253A10.1007%25252Fs11427-012-4330-y.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs11427-012-4330-y*~hmac=4b04eb9876c5969d6fddce76ade0191d973930876be776510bf307112e4d130c

http://www.nature.com/nature/journal/v435/n7043/full/nature03610.html

and while the field is still developing (P and other nutrients have been understood much better) there is also plenty of evidence of transfer between plants via the myc. network

http://www.nature.com/nature/journal/v388/n6642/full/388579a0.html (large trees feed smaller trees via the network)

If you look at these and similar papers you see that for most plants (most vegetables) the non symbiotic state is "unnatural" (their words). The problem is not the effect, which is large and even dominant*, but rather the reproducibility of it, since it is a complex phenomenon, which can not be explained or predicted using our chemically based rules. Also, it takes a long time (years) to have a robust myc. population. If one tills, he never gets there.

* the network increases the volume of soil accessed by the roots by a factor of ten or more. Its main proven effects are resistance to drought, disease, and it keeps out heavy metals. A good network is essential to establish a nutrient cycle and make the system sustainable.

glib, I haven't read those links, but trusting your interpretation, it seems good to note that any measure of 'symbiosis' is not between 'companion plant' species, but rather between individual plants and soil fungi - Mycorrhiza. Now, whether 2 or more species of plants more easily form relationships with the same fungi... well, that may be what is somewhat less understood.

Yes, I don't regard fungus as a "companion plant". I was referring to legumes as a companion plant and legumes, while they can produce soil nitrogen, don't obviously do it while they're alive.

yes, the relation is not direct but mediated. Those in the field are, more or less, all coming from the same premises: why does a native prairie put up 8 ft of growth every year without water or fertilizer? From this (and a lot of studies to back it up) they come to the realization that biological processes predominate, that a prairie can get its nutrients to cycle, and that the whole system is more efficient at turning sunlight into bio-mass. From this they place diversity (extended companionship) among their soil health principles.

I started doubting conventional wisdom based on two facts: the first is that 3 strong amendments with compost pushed my P, K levels above optimal. And indeed fertility has not improved. Second, it happens every year, in particular with chicory plants but also parsnip, that seeds accidentally dropped in the paths grow BETTER than seeds dropped in the beds. But the paths received some wood chips 6 years ago, now are just grass, and they have not received the big compost loads. Why does radicchio grow better in the paths every year? I alternate it with non-mycorrhizal plants (collard or lacinato) in the beds.

I guess there are different ways to take the term "companion plant" by the replies in this thread.
I take it as all the things that make for a companion, not just if there is one specific chemical interchange between two plants. Insect and pest management is part of companion planting IMO- so is knowing what will grow badly by each other, AKA being a bad companion. Nutrient, light, and water needs also play into what makes for a good or bad companion. Intercropping, succession planting, crop rotation and cover crop use all play into what plants are best to companion up or be follow up companions. The garden is really a whole community.

Unfortunately, the whole complex topic of how the garden gets along or not has been distilled down into a few charts and a huge list of anecdotal evidence and very little actual studies about those particular anecdotes.
It's kind of like how the word diet used to mean your entire eating lifestyle. Now the word diet has been distilled down into charts and lists of magic combinations of foods and people telling you how well that works or not.

I don't really believe in a lot of the anecdotal evidence that goes along with companion planting, like basil makes tomatoes sweeter. I would rather like to see more studies on these points.

I think some of this thread has been about redefining the phrase "companion planting". Sure, one could say that bees are companions, and soil is a companion, and air is a companion. Certainly gardeners themselves are companions, because they nurse their plants and help them grow. But the way the phrase "companion planting" is normally used is that planting one plant next to the other plant helps both plants. As far as I can tell that's largely based on anecdotal evidence. The trouble with anecdotal evidence is that if it seems to work for you, you get excited about it and tell people about it. If it doesn't work, you tend to ignore it. I have tomatoes partly shaded by an oak tree. They grow great. So always plant oak trees next to your tomatoes!

Agree that the discussion has gotten way off base. The concept of Companion Planting already has a very specific definition and much of what has been posted in this thread has nothing to do with it. I sincerely doubt that the authors and advocates of it would appreciate having the whole thing re-defined for them.

Dave

digdirt2, if I Google "companion planting" much of what was discussed here does seem to fit that definition. What is your definition?

As already mentioned it does NOT include nor make any mention of things like biomass optimization, nitrogen fixation, root surface exposure, or symbiotic fungus/Mycorrhizae, etc. in any of its publications. That is not what we are talking about.

As Dan said if ones broadens the definition of it that much then you might as well include the gardener, the soil, local weeds, your variety of oak or hemlock tree, etc.

Look at how the founders and practioners of it define it - "companion planting is based on the theory that certain plants can either enhance, or in some cases inhibit, the growth of others." "Companion plants insure a happy garden."

So all their charts are limited to Plant Companions: friend or foe. Corn loves peas but hates tomatoes, tomatoes love carrots but hate cauliflower,etc. Why? They don't know or care.

Dave

The Wikipedia article shows a pretty broad definition that includes some thought out/scientific reasoning. Who exactly is "they" that own the phrase "companion planting"? I agree the phrase is usually thrown around as nonsense.

https://en.m.wikipedia.org/wiki/Companion_planting

to be honest, I consider companion planting as is usually presented similar to planting with the moon. No scientific basis. But plant cooperation, and plants as part of a biological system, is scientifically proven. There are consequences, which range from large to non-existent depending on the type of plant and locale. Soil science has progressed quite a bit since the chemistry-is-all mafia retired.

My idea of companion gardening is to aid in insect control & save space. For example I plant hot peppers next to tomatoes & pumpkins with corn. The hot peppers keep tomatoes pest free and the corn gives shade to pumpkin during hot days.

The OP said "We are planting the biggest vegetable garden in our lives and I want to try that if seems right." No, they don't want to know if plants are part of a biological system, no, they don't want to know what to plant for next years crop, and no, they probably don't want to know if they should plant any fungus with their crops. What I assumed they were referring to was to plant stuff that helps other plants nearby. So Dave is right. This discussion has departed strongly from what the question was originally about. So as far as I'm concerned, the OP owns the phrase we're talking about in the thread they started.

You can start another thread about "What are all the definitions of companion planting", but I probably won't participate in that one. Really, aren't we done here?

I was stressing the difference between companion planting as it is commonly known, and the concept of symbiosis between plants, where individual species do benefit from plants association in a variety of ecosystems. It is not the first time, I assure you, that a thread takes a tangential direction. On the other hand, companion planting itself can be dispatched with "not proven, not easily replicable. the end".

I have to disagree with my last post. This paper

http://www.plantphysiol.org/content/159/2/789.full

states that in fact in the presence of a myc. network and both flax and sorghum present biomass increases. That is, the total biomass is 11% higher than if the two plants are grown separate (they did not measure seed yield). Tracing the nutrients, sorghum gave a lot of them and lost 7%, but flax (which got essentially all nutrients from the myc.) gained 46%.

Under these circumstances (presence of a particular myc.), it seems that sorghum is a good companion for flax. It is a good paper, cited by 81 in 3 years. It fulfills the definition of increased production through association.

And believe it or not, it is not cited because they show companionship effects (it is such a trivial result, a diverse ecosystem has been shown nearly everywhere to be more productive), but rather because it shows great asymmetry in nutrient exchange (sorghum gives most carbon to myc., while myc. gives most P and N to flax). Indeed sorghum is an ideal, giving companion for flax.

You guys are too intense for such a simple question.

Well, zzackey, next time you grow flax, you'll know what to do!

Flax, I don't get it.

Well, if you get tired of vegetables ...

The problem of the companion planting concept is not that it is untrue, because improved production through symbiosis have been observed in so many ecosystems that it is background information (except for those that formed their knowledge in the 1980s then stopped). The problem is that you can have also delayed effects, if the basic effect is to keep your myc. strong. In short, it is not the whole story. This is why millions of farmers use a technique essentially ignored in this forum, called "cover crops". Cover crops always have a strongly mycorrhizal plant in the mix.

To me, the attraction (apart from the scientific achievement, which is always something) is that it provides a working hypothesis for problems I could not understand. I hope it is not too much to solicit the opinion of the great experts that came so strongly against the hypothesis, and see if they can explain it based on what they know. These are the two clearest for me, but there are two more.

Background: I have 21 beds, and cultivate about ten beds of non myc. vegetables. The fraction of non-myc. is unusual, I have opinions on what is healthy and productive, but that means every myc. vegetable follows in the rotation non-myc, 100% of the time.

I have already mentioned that radicchio grows better in the paths than in the beds. It has happened already three times. The paths have grass, the beds get fertilized, mulched, watered, and I do a decent job of weeding. Why is that?

Second, no one at the local market sells garlic bigger than what I grow. But spring onions, seed, my transplant, or set, have always been disappointing. Further, already two years in a row I got much larger overwintering onions than regular onions (Keepsake from Territorial). Why? If anything, the onions always get fertilized more (urea only, I have 300 ppm K and 80 ppm P, too much).

glib, how do you grow such big garlic? I've never tried to grow it.

I have a very fertile soil, because I placed about 6-8 inches of compost on every bed. It analyzes to 21% OM, with very high Ca, K, P and Mg. The real problem is why garlic grows and onions do not. Both plants are what are called "obligate mycorrhyzal", they need the network to thrive (they have the shortest, lowest surface roots of any common vegetable, they need the network to extend them). If you have it, garlic will grow great. In my rotation both follow brassica, but the basic difference IMHO is that garlic, with sugars to give from a large seed, has four months in the soil to form such connections. Grass-like onion plants do not have it, have to grow right away, and do poorly. This year I planted onions after tomatoes to get some.

Anyhow, Zackey, you asked a question, here is my answer:

there are five principles of soil health, which are rather different from common wisdom from 30 years ago. It is good to have principles because every site, soil, climate is different, but following those principles generates positive outcomes all over the US. you can find presentations about soil health on youtube, or at the ATTRA, SARE, Rodale, and USDA NRCS sites. If you want a fairly complete presentation, this one by Gabe Brown, a farmer who works closely with a strong group of soil scientists at NDSU, is good and complete (it was my first one, and I chanced on it while trying to help my daughter with a college assignment. Since then I read dozens of scientific papers)

https://www.youtube.com/watch?v=9yPjoh9YJMk

If you want something more inspiring, Ray Archuleta of the USDA NRCS is the ticket. All his videos are posted by someone who went to listen to him, but he posted a single one, where he shows how he prepares his vegetable garden, that will shock you as it shocked me. It involves his daughter's car.

Most of these principles are aimed at optimizing the biological activity in your soil. From it fertility follows. You are interested in vegetable companionship, you can sidestep the polemic and head to Wikipedia where you can search "Intercropping". It is the same thing but one thousand years old. Look there and you will see that, say, tomato and carrots follow the guidelines. They have different root canopies, different light requirements, and use different nutrients. Both feed the network, to their advantage and for the advantage of future crops.

But the greatest damage done to the soil are heavy tilling and letting it lay fallow, so the greatest help comes from avoiding those. Winter cover crops provide for that, while providing extra carbon and some nitrogen to nourish the soil. You are in the South and you can even use summer cover crops, between spring and fall crops, which are incredible soil builders, such as sorghum and crotolaria. Cover crops should also have a deep rooted fraction that is essential to great soil. Sure carrots are good (go down to 8 feet) but carrots or others, you have to build those channels that go down to optimize the physical properties of your soil. Cover crops can be dispatched in a variety of ways, the simplest is to use crops that winterkill. Plenty of material on youtube on that.

These soil scientists are so visible and are beating their drum so much because they think that you can build ultra-fertile soil (chernozem, basically) in 5 years, which is a lot shorter than the 1000s of years nature takes. If you start by cover cropping in winter, and never plant a bed with only non-myc. vegetables (ha! I was the worst offender. I like my garden neat and ordered. In fact, a good garden needs to look messy), you will be on your way. I plant cabbage in clover and arugula, tomato in a variety of things, mostly chicory and corn salad, interplant parsnips with lacinato, and do other things if you are interested. But I started only 16 months ago, and I am still collecting data.