> Was this a "dumping ground" for culled seedlings or for soil that contained
> unsprouted seeds?
Pots of unsprouted seeds - and a lot of them that year. I'm in the habit of keeping pots through two seasons (mostly) and then discarding them. Too much work for too little return beyond that time frame but it does result in strays.
>Were these OGB- type seedlings traditional
> first-generation quarterbreds or were they from wide crosses?
They should have all been 1st gen cross of TBxAB types. Other types were dumped in a different place. Pots that sit around for 24-30 months or more are exposed to squirrels, mice, toad frogs and birds digging in them from time to time, not to mention occasionally being tipped over with the spill scraped up and put back in the pots. Especially tricky if more than one pot is tipped at the same time. Quite often I find seeds on the surface and push them back under the soil. While in the pots, different types aren't segregated so my speculation is that a varmint moved a seed from one pot to another and this is the result. A reasonable scenario based on its appearance?