I’m planning a new landrace beginning for my garden this year. Cucumbers which are resistant to bacterial wilt transmitted by cucumber beetles. Every year so far my cucumbers kick it midway through the season without giving me many cucs. I’m tired of this!! So I’ve gathered about 20 dif varieties. A few are hybrids. I also have a grex from Experimental Farm Network and a grex from a friend’s garden. I got as many varieties that listed disease resistance as one of their traits as I could - not sure if that matters much. I also want sweet, bitterfree cucs for fresh eating with a thin skin preferably so have favoured that type in my variety selection. No pickling cucs are included. I have a small garden so will only be able to plant one plant per variety. I’m excited! My challenge will be not babying them and letting the ones die that are headed that way. Also ripping out any infected plants. Thoughts on timing and culling would be appreciated - since the disease usually only shows up halfway through my season, some fruits will likely already have been pollinated of and by the plants that don’t have any resistance. Or should I just save whatever seeds I get this year and not worry about culling at all?
Should add that I’m in zone 4b, eastern Ontario, Canada.
I suggest you save the seeds from everything that gives you seeds in the first year. Even if they may have been pollinated by plants that don’t have the disease resistance you want, they will have their mother’s disease resistance, and you never know – the disease resistance may not be passed down through Mendelian inheritance (mother and father’s genetics), but cytoplasmic inheritance (mother’s genetics only).
Plus, it’s entirely possible some of the tastiest ones will be the least disease resistant, so giving them the chance to contribute some pollen may eventually result in your favorite flavors resurfacing in plants with the disease resistance you want.
And of course, it’s a good idea to save all the genetic diversity you can for the first two generations, and not start selecting for much until year three. Make sure the genes have gotten all mixed up and you have a wide variety of different random crosses to pick between.
That said, feel free to plant way more seeds from your best plants, if you want to, next year. You probably want to keep the genetics from the mediocre ones around, but that doesn’t mean they have to be planted in the same proportion as the best.
My plan with my zucchinis is to plant about 5 of my favorites for every 1 that was meh. Keep the genetic diversity around, but encourage the population to give me more of what I want.
Great project! So curious to see your results! I have the exact same problem! I’ve dealt with it by planting way later and selecting for super early producing varieties. That works but leave me with no cucumber for most of the growing season so I’d be really interested to know how your project evolves. I might try a similar project if I get the time! Good luck, keep me posted.
Sounds like a good project, Aislinn! We are also working towards this same goal. We are also in Canada (Nova Scotia), which would make it easier to share seeds. Would you be interested in a trade?
Absolutely!! Where are you at in your process? As I said I’m just at the very beginning - well, haven’t even started yet! lol
Buuuut, I’d be happy to share seeds of all the varieties that I’ve gathered. 
I will!! Thanks. I’m happy to share seeds when I get some success too.
I just started a grex in 2022. So I still need more varieties to get a wider genetic base before selecting much. So it would be an advantage to share. We always have some plants that get eaten and we allowed those to self-eliminate! So we have made an inch of progress already…
Great! Just wondering… do you have pickling cucs in your grex? Not sure if I’m just being weird trying to keep those out of mine or not. lol
Also, not sure how we private message on here, but will sort that out so we can share addresses for swapping.
Thanks so much!! It seems easy for me to get caught up in attempting to control the development of the landrace in the beginning. I have to keep reminding myself (or get reminded by kind folk like you) that this is not how it works best - that the “laziest”, easiest method is usually the way to go.
Thank you for the reminder!!!
Raoul Robinson, in Return to Resistance, suggests that in the first year we cull only the healthy plants. Because their resistance might be due to a single gene that will eventually succumb to disease. Then, the susceptible plants can shuffle thousands of genes to come up with the combination that most successfully defeats the disease long-term, because there are thousands of genes providing a tiny amount of protection instead of one failure-prone gene offering a huge protection. The many-gene protection model is commonly called horizontal resistance. The one-gene model is commonly called vertical resistance.
More than a decade ago, Raoul’s work inspired me to develop the principles that I now call landrace gardening. I advocate allowing only the ecosystem to do the selection during the first year. Anything that is able to produce seeds gets planted the second year, (perhaps favoring the sowing of more productive types). Again, allowing the ecosystem to do the culling. Then in the third year, selection can begin for things like flavor, productivity, color, etc.
Those first few years of non-culling are critical to long-term success.
p.s. The unstated corollary to Raoul’s methods, is that varieties with known disease resistance would not be included in the initial planting. My strategy is to not worry about it. I don’t have a DNA lab, so I really don’t know what’s going on at a genetic level.
Thanks, Joseph!! Thats really helpful.
Wow, the advice to cull the healthiest plants in the first generation is completely counterintuitive!
It makes sense if you want to get rid of easy short-term solutions in order to favor hard long-term solutions that would be hidden by the former, however.
I’m lying here in bed now unable to sleep because I’m thinking about cucumber landracing! Wondering if i need to rethink my “plan”. I choose a bunch of varieties that listed disease resistance as a trait, and now it seems, based on Joseph’s info, that that may be the wrong way to go. Ahhhh!! My overthinking brain is having a field day!
I started a cucumber landrace this summer with the same goals that you have, and kept seeds from all the plants that produced fruit, as per Joseph’s advice. I’ll be adding more varieties this year, including the second grex from EFN. (I don’t mind mixing pickling cukes with others, I don’t think they’re really that different.) But here in New York State we had a very dry summer, so all the usual cucumber problems never appeared. Instead of selecting for insect and disease resistance, I ended up selecting for drought tolerance! This year I assume we’ll return to “normal” weather - unless summer droughts become the new normal. The point is, you never really know in advance what you’ll be selecting for.
You know what? After thinking about it, I wouldn’t pull out the healthiest plants, even if they might be healthy because of vertical resistance. They might also be healthy because of horizontal resistance, and honestly, if my goal is healthy plants, I don’t care which mechanism is helping, I’m going to select for healthy plants. I bet the two can work hand-in-hand in a synergistic way. Especially since genetics are messy – what looks like a single-gene resistance may actually be a bunch of closely linked multi-gene resistances, for instance.
Anyway. I wouldn’t pull out the healthiest plants, no matter what. I would just make sure to save seeds from those and the ones that look somewhat disease resistant and not fully. Then I can let the plants show me which genes are the best in subsequent generations.
Agree. It suits the lazy gardener in me too. And the one who would have A LOT of trouble pulling out a healthy plant. I get the theory though.