Difference between a grex and a hybrid swarm

General Discussions
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Grex:
A mixture of widely different varieties grown together for a generation. This can be a bag of 15 beans from the store, 50 heirloom tomatoes, etc. These are the seeds you’ll use on your 2nd year of growing if you’re starting your own grex where seeds have started to cross with one another. These are also the ideal for us to trade around the group because they’re more likely to survive in more environments and still have as much variety as possible.

Hybrid Swarm:
This is where the different individual varieties have mixed and now “none” of the seeds are a unique heirloom anymore. If the plant readily cross breeds then this is year 2 or 3 of making a landrace. A hybrid swarm can also be created by someone hand mixing hybrids and then just gathering all the different hybrids together.

Original Post: (included so that the comments make sense)
I think I have in my head a different definition for a grex than others do. I’m wondering what we mean when we say grex.

My current understanding:
A grex is a bunch of seeds with tons of variations in them. Not a bunch of different types of heirlooms, but rather a bunch of seeds that are hybrids of heirlooms, f1 hybrids, and wild seeds. To me very little to none of the seeds that you get in a grex are heirlooms anymore. They’ve all already mixed with something else so that none of their children will be true to type, but they’ll all have as much genetics per seed as we can mix in.

What it feels like some people define it as:
It feels like some people believe that a grex is a bunch of heirlooms planted together.

Ways to make a grex:
I see a few different ways to build grexes

  1. Forcing crosses - plant a bunch of heirlooms and do as much hand crossing as possible when required (or letting them mix naturally if they do that).
  2. Collecting landraces - pulling as many landraces as possible and planting them together (this is one of the cool ways that our group can help big time)
  3. Natural crosses - planting a bunch of heirlooms together, letting them cross over the years and saving seeds specifically from children that have obviously crossed. This seems to work best for plants that cross more openly and is the primary reason for the promiscuous tomato project. The more plants we can get to cross more openly the easier it is to make grexes and then landraces.

Why the post?
I just want other people’s thoughts. Am I wrong in my understanding of what a grex actually is? Are there other ways to make grexes? Can we work as a group to form more and more grexes, adding additional diversity as we go?

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Neat! I think this is totally worth checking in on so that we know if we’re communicating well.

If you read the Wikipedia article on grex, it is a word specific to orchids, made to handle their propensity for interspecific crosses, but otherwise fits what you’re saying.

As to “what a grex actually is”…it’s a word and if we all use it to mean the same thing, even if it’s different than how it is used in other jargon-contexts, then we’re using it right because communication is happening. When we talk to orchid breeders, confusion is definitely possible.

I do refer to my mixes of commercial varieties as grexes and even talk about “grexing up” these seeds. I think of the grex as a stage before a hybrid swarm is developed, which is a stage before landraces are developed. Do you have an alternate word in mind for what we’ve been calling grexes?

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I’d call those a collection of different seeds that you’re bringing together to make a grex :slight_smile:. Or just a variety of genetics. I would even be ok with pregrex or genetics for a grex.

The reason I think this actually matters is that sharing a grex (as i’ve defined it) is very very beneficial to our group as a whole, where as sharing one of these pregrexes isn’t really all that useful. I suppose it has it’s uses, but it’s very easy to do in other seed sharing groups - you simply join a variety grow out group and you could easily have 20 or 30 heirloom varieties in 1 season to use to start your grex. But if we can grow out what i’m calling grexes then you have an awesome starting point for making your own landrace

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This seems like it could be described using simple terminology, something like “a diverse mixture of seeds”. Usage would vary and become more specific depending on the situation, for example: “a diverse mixture of tomato seeds”; “a diverse mixture of heirloom tomato seeds”; or “a diverse mixture of landrace tomato seeds.”

Edit: I have seen the term “breeders mix” used in places like the Experimental Farm Network catalog, but in my opinion that is a relatively abstract term that is probably more accurately described as either a hybrid swarm/grex, a diverse collection of seeds, or something else.

Edit 2: Are there any other Wikipedia editors around? It seems like the existing Grex article linked above needs to be updated to encompass uses beyond orchids. I would love to team up with someone else to reframe that article :smiley:

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Here’s my definition…

Grex: A mixture of widely different types growing together. (This definition says nothing about how they originated, or whether they are locally adapted. This definition addresses only the condition of widely different varieties planted together.)

In the case of highly inbreeding crops like common beans in my garden, the grex can be thought of as a mixture of different varieties growing together perpetually.

In the case of highly out-crossing crops, a grex quickly turns into a “hybrid swarm”, and the individual varieties get lost. As the hybrid swarm becomes locally-adapted to the location and community, I consider it to move through a proto-landrace stage, and then finally becoming either a landrace or a variety, depending on how much inbreeding occurred.

By this definition, landraces are less genetically-diverse than grexes, because the genes that do not contribute to local-adaptation have been mostly culled.

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interesting, so you’re calling what I’ve been thinking of a grex as a hybrid swarm. So then hybrid swarms are the truly valuable thing for us to be trading around.

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Plant breeders say that the most interesting generation is the G2. That’s where the most diversity shows up. I think that applies to landraces as well.

1st year. Gather up a bunch of different types of seeds, (I call that a grex) grow them out. Many die, or do poorly but produce some pollen or seeds.

2nd year. (out-crossing species). This is the generation with the most diversity. (I think of it as a hybrid swarm). All kinds of wonderful and unfortunate traits show up. The best dramatically out-produce the pikers, skewing the population strongly in the direction of the best seed producers.

3rd year. The magical year when the offspring are mostly descended from ancestors that thrived in the previous two generations.

In a perfect world, I prefer to share the 2nd year seeds. That’s where the population has the best chance of thriving under whatever conditions happen to exist in it’s new location.

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Cool. I’ll update the main post and this will be more informational so that we all use the same language.

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I prefer sticking to the ‘dictionary’ definitions where possible. In horticultural terms a grex now means the offspring of a cross (it arose among orchid growers as pointed out above).
Throwing seeds together is just a mix and for an inbreeder is likely to remain just a mix for some time.
You could also have a mix of hybrids if you collected a heap of F1s and put them together. To my mind this is not a swarm.
A hybrid swarm is, to me, a collection of hybrids arising from a mix.
Personally, I avoid both terms, grex and hybrid swarm, as different people mean different things. That’s not likely to change I think.

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I think the distinction between inbreeding and outbreeding crops as Joseph mentioned is very important. Beans for example which cross but only very occasionally, I still think of as more of a mix.

Things that cross easily like brassica after the first year, to me are becoming a grex. I also think of the grex as those that by chance only crossed with their own kind, those that did cross, and whatever re-crossing in subsequent years all being grown together, generation after generation. Crossing and backcrossing repeatedly. This I think probably results in the most diverse expression of genetic possibilities.

Either way, a highly diverse mix of inbreeders or a grex from outcrossing, over time ends up as the landrace. The grex is really better for it I think because even if something selects itself out as the mother plant it may have still contributed pollen.

With the inbreeders if conditions kill off an initial variety, it’s just gone. That could be remedied to some degree at least with hand pollination, but I just don’t really have the skill and patience to do that. Bees have helped me there some with beans but so far, I haven’t seen any indication of it with cowpeas, soybeans or peanuts. I guess for now I’ll have to be happy with just a mix on them but all I’ve planted have done well, none have selected themselves out.

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In my thinking a hybrid swarm is a term used for interspecies crosses. Which is a phenomenon found in nature where two closely related plant species come together, and species barriers break down. I don’t think you’ll hear me use that term for within species hybrids. My squash patch is a hybrid swarm because there are interspecies hybrids and so is my tomato. My sunflower patch is not- but it could be if I got some more sunflower species that could cross. There is such a sunflower species out in Eastern Montana. Hybrid swarm Definition & Meaning - Merriam-Webster

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it feels like we as a group should agree on the definitions. I tend to agree with William and Mark but as long as we can agree on a definition internally at least we know what people are talking about

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I think we need more than an agreement among the people who post here so that new people who come to the discussion or even to the classes can start on a firm foundation. We don’t really need to agree but rather to decide and explain. When I first started thinking about it, I thought it might be relatively easy but unfortunately, I doubt that will be the case. I’m also afraid it won’t be brief.

Still, I think it is necessary. It might even warrant an actual class, perhaps a “suggested” prerequisite or at least with a link prominently displayed while taking the classes and here on the discussion pages.

As an example, I’ll start with defining “landrace” as per merriam-webster.com and then follow with how I see its application to the classes and discussion.
“a local variety of a species of plant or animal that has distinctive characteristics arising from development and adaptation over time to conditions of a localized geographic region and that typically displays greater genetic diversity than types subjected to formal breeding practices”

Logically, and briefly, the foundations of these landraces evolved on their own long before humans even existed, let alone began practicing agriculture. Later as humans brought wild plants under cultivation these wild food plants, over long periods of time partly just by having been introduced to agriculture rather than growing wild, and partly through human selection for desired traits, evolved into what might be described as regional landraces. Trading between and migration of indigenous groups brought genetic diversity into new areas where lacking the formal breeding practices used today, these cultivated crops by selection through climatic conditions and human preferences became productive and resilient sources of food.

With the arrival of European colonists some of these crops were adopted and some were discarded. A greater emphasis on production and selection for preferred traits and later even more formal breeding practices became the norm as did new, to the crops, cultivation practices. Farmers and gardeners were rewarded with greater harvests, but it came at an unforeseen price. Larger and larger mono-culture fields of more and more restricted genetic diversity gave rise to more and more aggressive disease and insect pressures and less and less ability of the crops to adapt. Soils didn’t just become depleted of nutrients but were eroded away by aggressive mechanized tilling practices.

The response over the last century or more was to compensate with the use of chemical compounds toxic to the insects and disease organisms and the addition of mined or synthesized fertilizers. Today, to a large degree, the crops don’t need disease resistance, genetic adaptability or even living soil. This, arguably, has worked well for the last several decades but has also come at a perhaps less unforeseen and even higher price, which will not be detailed here.

Landrace Gardening is simply a method, applicable on any scale, that seeks to restore productivity through genetic diversity and adaptation rather than chemical intervention.

**Way too long, especially since just one of many terms that need settling. O’ well I gave it a shot.

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As a grass-green newbie to gardening in general, and landrace gardening in particular, I heartily affirm the need for commonly held terminology. Especially as I’m trying to explain my efforts to others. Also if (as I presume to be the case) the unbolded text is your own writing… no, it’s not too long an explanation. It just means you have a book in you. :slight_smile: That is a very good thing indeed. Write much more.

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I appreciate the goal for standardizing language across everything and am ready to update the definitions in the course lesson as soon as we agree!

I propose spending a few minutes on it on our call on Feb 12th and coming up with some final language.

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I like and agree with your language, but I think it has a North American focus that I think we could broaden since there are landrace varieties all over the world that go back to prehistory in many or all cultures with agriculture.

It’s my understanding that inbred, narrowly selected breeding has been around for a long time but has not been the norm in terms of feeding the world in any region until modern times. But I digress.

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Yes, that occurred to me a well. Didn’t say it would be easy or quick. :grin:

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William, when the discussion on Claytonia started, I read up on Wikipedia just be barely familiar with what was being discussed and found this sentence (somewhat related to what we’re discussing here):

Together with two other Claytonia species, Claytonia parviflora and C. rubra, C. perfoliata comprises what is almost certainly a polyploid pillar complex, which is based on three diploid species.

I started to try to figure out what a pillar complex is – I can derive a little bit of meaning just from the context and knowing a little bit about weird ploidy phenomena, but I ended up giving up before I was really satisfied. Is that a normal botanical term and can you provide a layman’s definition?

On the topic of the more general definitions, I take it as a given that we’re using Joseph’s definition of landrace since we’ve more or less aggregated around that one foundational droplet, even though plenty of people disagree with details of that definition.

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I agree so I’d like to throw in the definition from Landrace Gardening below but I’m not 100% the first sentence agrees with the third sentence, and I am not a very detail oriented person so it never mattered to me that it might be confusing or that it really mattered exactly which year the grex actually starts… :smile: :heart_eyes:

Grex
A grex is a bunch of varieties growing together. To create a grex, plant approximately equal amounts of seed from different sources and varieties. It is common to plant together the seeds from 5-50 varieties to make an original mass cross, which is called a grex.

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Sounds good to me.