My concerns/question is about how to keep the original variety from cross pollinating with another. Do they require isolation to eliminate cross pollination? I’m pretty sure some of you save tomato seeds and can advise me on how to keep the seeds pure. Any comments are welcome. Thanks
I don’t know the answer to your question Bill. I would suspect they would need to be grown in while being relatively isolated from other heirlooms. But if I’m growing all heirlooms I would be fine with cross pollination. Could lead to an incredible new variety.
Keep them as far apart as possible. Always keep a few years worth of seed. If last year’s crossed go back to the previous year. Also take the first tomatoes for seed. They are the most likely to be true. Bees are not around early. They must be self pollinated.
The thing about new crosses is it takes about 8 generations to stabilize genes. Eight years before tomatoes will come out true to parent plants.
It’s not a practical issue with tomatoes so long as there is at least a little separation. A couple of feet is fine.
I assume that that would be because the pollen is typically from the same flower as the fruit.
About 10 feet should be sufficient (source: Southern Exposure Seed Exchange)
Don’t forget to ferment your seeds first before saving them – in my experience it has made a world of difference.
edit: if you really wanted to be careful you could go the blossom bagging route: https://seeds.ca/d/?t=19d64c8600002698
I’d say it depends on how sure you want to be. The advice above is good - isolate if you can and/or bag the blossoms. But my experience is, without any separation other than grouping varieties in the rows (I don’t have extra room) I’ve kept multiple varieties going for many years without any changes that I can notice. Including one favorite that I’ve saved and grown for over 30 years now.
I do follow Drew51’s suggestions of keeping several year’s worth of seeds, and always take the first tomatoes for seed. Also ferment the seeds as figjamjar recommends. Kept dry and in the refrigerator, I’ve had almost 100% germination from 10 year old seeds, so you have plenty of generations to fall back on.
I never had problems with crosses on tomatoes, but I have had issues with peppers. A bell crossed with a green chili and I got these fat and long peppers that tasted like green chili peppers, pretty cool, I kept seed, but never grew them out. I also had a bell like pepper cross with Tennessee Cheese and results were small bells with a very thick skin. I didn’t like them.
I’ve never had a problem with my heirloom tomatoes crossing. In the beginning, I bagged the blossoms to be sure. Tomatoes are self-pollinating, so you do not need bees to help. That said, I’ve heard that high bee activity can sometimes cross pollinate. Later, I stopped bagging and just grew out a few plants from the new lot to make sure they were pure. In my case, I grow 3-4 of each variety (Brandywine from Croatia, Cherokee Purple, Opalka, Heidi, Speckled Roman, etc) in VERY close proximity to each other and they have never crossed. And I had a large amount of bees. Unless you are planning of trading the seed before growing them out, I would not worry about isolation. Also, as several people has said, make sure you ferment! It is only a few days, but rather stinky.