I would split them - two plants growing that close is not efficient for yields and can cause disease issues. Tomatoes are quite vigorous so just cut off some of the bottom leaves and bury them deep and they should recover.

I like the expirament idea. Especially if you have more plants where the production from one plant isn't going to make or break your season.

Another option would be to separate them. Very gently massage the root ball to let the soil (or soiless mix) fall out and then you just lightly tease the roots apart. Generally you would start from one side and just tease and pull gently, they will separate fine. Then plant those suckers up to the bottom of the top leaves and watch em go.

Here's a recent thread on this question:
http://forums.gardenweb.com/forums/load/tomato/msg0416423316939.html?14

As long as you give them enough of everything for two they should make fruit.
The problem is air flow & it is a small problem if you watch the plants.

If you'd have separated them and transplanted one of them to its own container when they were young it would have been easy. Now, not so much. In fact now, it may be impossible without risking both. So just leave them as is and plant.

But next time do them both a favor and separate them - there is no need to kill one of them. That way they both get the chance to live.

Dave

Thanks for everyone's input. I actually already separated all the other seedlings when they were smaller- just thought I'd see what happened with these two. I think I'll leave them intact and plant them together, knowing that they might produce less, be more susceptible to disease, etc -- I have enough plants that I could afford to lose them, so might as well see what happens. The other thread had similar advice (many people suggested separating them), but no one knew what would actually happen to production. I'll plant them next to a single Sun Gold to see how they differ and then report back at the end of the summer! :)

Um, what's the difference having two seedlings in one pot vs one with many stems? If you have one and don't prune, you will have quite a few stems eventually. By comparison, you could have two seedlings and prune them both to one or two main stems each, and end up with fewer "plant" than in the other situation. Just seems like you should be able to manage it just fine.

I know it is a year later, but how did it work out for you? My mom has been planting tomatoes in pairs all her life and she has always had enormous yields...She does prune all suckers off though, so each plant has only one main stem...

zornitzayoung, why not just plant a single plant and don't remove any suckers? There's no reason to prune except lack of space. If there's room for two plants, planted in the same hole, with one stalk each, then why not a single plant with 2, 3, or 4 stems?

I should add that I was raised to prune to the main stem, but realized how severely that limited yield.

Then again, I suppose there might be an advantage to 2 separate plants if the season is particularly short. The second plant would bear a week or two before the oldest sucker on a single plant would.

You don't give a location or a USDA zone, so I can't tell if that might be the reason.
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A few years back, due to family illness, I didn't start my own seeds. The plants I bought were from Bonnie, and many had suckers coming up through the planting mix (which didn't bother me -- and they were pretty determined suckers!).

The Black Krim turned out to be two plants of different varieties. When I realized that, I gave them more water than the other tomatoes, but for whatever reason, toward the end of the summer, the BK died. I don't know how typical that is when two plants are started together and barely pruned.

[The tomato that survived -- a dark pink egg that didn't match anything Bonnie was selling that year -- was one of the few highlights of a difficult year.]

Thanks for the reply. You see, this is the thing. She says that by removing the suckers the plant puts its energy into producing fruit versus growing more branches and leaves, and when you have only one main stem you can put two plant in the same hole. She swears by it and her yields are enormous. She lives in Europe...I like to research everything I do and so far have not come across anyone in the US who utilizes this method...I am curious if it really does work or if she just has good soil...I am in zone 7a in NVA and have limited space for my garden so I am tempted to put two plants together in each hole...

There was a question that wasn't answered there about 2 in one spot versus one with many stems... A significant difference between two whole plants versus one with many stems is that there will also be two whole root systems vying for nutrients and water, rather than onky one. Could be why the BK died.

zornitzayoung, as you probably know, suckers are the branches of the tomato plant.

Some people will tell you that suckers don't bear fruit: that's not true. Suckers on an indeterminate plant put out three leaf branches, then a flower truss, then continue with that pattern till frost (same pattern as the main stem, though IIRC the main stem doesn't put out its first flower truss until the root system is large enough, which is after more than three leaf trusses).

Yes, growing the sucker uses up some of the plant's energy: but the sucker's leaves then make more energy for the plant.

You may not find many in the U.S. who put two plants in one hole and prune each to the main stem, but you will find plenty who advocate pruning a single plant to the main stem (as my grandfather and mother did). I think at least half the growing advice on the Internet takes that position, and many repeat the notion that suckers don't bear flowers or fruit!

I would credit your mother's success to good gardening, good soil, good weather, and lack of disease organisms.

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sunnibel, yeah, I've wondered ... but who knows for certain.

She says that by removing the suckers the plant puts its energy into producing fruit versus growing more branches and leaves, and when you have only one main stem you can put two plant in the same hole. She swears by it and her yields are enormous. She lives in Europe.

She probably learned all that from her parents and grandparents and back for several generations because no one knew any better. And she's happy with it so isn't going to change her beliefs or even agree to try something new. It is a waste of time to try to tell her.

However that does NOT mean that it is best or even true - it isn't - just that it believed by some. And it does not justify, given all the overwhelming research and evidence to the contrary, that her method should be passed on or used by modern growers. They should not.

As my Mama used to say, "just because someone else jumps off the bridge does that mean you have to do it too?"

So it's your choice how you plant your tomatoes - Mom's way or the better way. But I sure wouldn't encourage others to use Mom's way.

Dave