When planting tomato seedlings (purchased in 4" pots), I often have 2 or 3 plants per pot and sometimes the seedlings are very close together. These plants will be transplanted into 4 18" pots. My question is: For total poundage production, is it better to transplant the 4" as is, break apart the seedlings and plant 2 (or more) in each pot, or thin and only use one plant per big pot?

I do worry that separating plants this close together will cause distress or death of one or both.

Additional information: Zone 13(Sunset Guide)/Zone 9(USDA), plant in February to early March for fruit in May and June, I do not try to keep plants going through the summer, it's just too brutal.

tomato seedling tomato seedling close up

  • 1
    Not really an answer, but growing Eggplants (same family) in a commercial hothouse, we were advised that growing 2 plants per bag was ideal - that said, the 2 plants were still separated by a few inches. I understand that nightshades are quite tolerant of root disturbances, so I would guess separating them out would be a good idea.
    – davidgo
    Commented Mar 2, 2017 at 19:39
  • What kind of tomatoes are these plants? Commented Mar 4, 2017 at 10:06
  • The pictured plant is Celebrity (hybrid), I also have a bonnieplants.com/product/roma-grape-juliet-tomato (which is new to me) with 2 seedlings right next to each other.
    – Debbie M.
    Commented Mar 4, 2017 at 19:21
  • Also, if you want to maximise yield, you should be fairly brutal with pruning.
    – davidgo
    Commented Mar 5, 2017 at 21:47
  • @davidgo not according to this answer gardening.stackexchange.com/a/8058/11461 do you have more info to back this up?
    – Debbie M.
    Commented Mar 5, 2017 at 23:59

4 Answers 4


Normally in such a situation, if I were faced with this issue, I would split them.The fact is that tomatoes make roots very fast and given the right growing conditions would quickly recover from being split. I would take a sharp knife and insert it between the seedlings and cut down through the roots with a slight sawing motion to disturb the roots as little as possible, then replant the two halves in new potting soil deeply so that the top growth of each one is buried to about half its height. It will quickly make roots along the buried part of the stem.

However you mention that a hot season is approaching; it will take about a week for the two separated halves to get back to full speed, which might be a significant stop for them. In that case I would plant as is and train the two shoots into a V shape, 60 degrees to the horizontal to give maximum light to the two sides and give close attention to adequate water and nutrition.

If you have several pots, divide into two groups, split half and leave the others intact. Then you are covered in case the hot weather is slightly delayed.


From my observations and experience, most of the time you can expect smaller fruits and less production from two all-season tomato plants in the same location in the ground than you can from one tomato plant by itself.

I'm not sure if the answer is the same for tomatoes that are kept in containers as their final destination. I'm also not sure about determinate tomatoes that only fruit once and die. How you fertilize might also affect the answer. (My experience is without much fertilization.)

Anyway, it's possible that the variety is one that does well with two plants in the same spot, especially since you purchased the plants this way. Vendors seem to do things the way they do them for a good reason, usually. Asking the vendor their reasoning may be a good idea. You might email or call the company. I'm not sure that a customer service representative will know their methodology, though.

Your two plants seem to be the same size. That's a good sign (one plant doesn't seem to be dominating the other, anyway). Some varieties might do fine with two plants in one spot (and I'm pretty sure if one were dominating then it wouldn't be one of those varieties). However, there's no guarantee that you have a variety that does fine with two plants in one spot, just because one isn't dominating.

FYI: I have a hypothesis that tomatoes can be acclimatized over the generations to producing better with two or more plants in the same spot. I'm in the process of testing it with Pruden's Purple.

FYI: Watermelons and muskmelons rarely seem to be bothered by having multiple plants in the same spot (I think there are some varieties that aren't used to it, though). So, what's true for one species may not be true for another.

I wonder if your plants are indeed two separate plants or not (maybe they're just the same plant buried deeper).

Anyway, doing one plant per pot is probably the best idea, unless there's something special about the tomatoes. I would only be very concerned about dividing the roots up if soil diseases are a significant problem in your area or if they're in your soil.

If you want to divide the roots up, you can take the plants out, massage the soil to loosen it, and carefully pull the two plants' roots apart (gently pull a little and stop and pull a little and stop, until they come apart). They can sometimes come apart without much, if any, ripping, that way. Just cutting them should be fine though. Then transplant them into their own pots.

I wouldn't disturb the roots if you're not going to give them their own pots, though. I would just keep them as is and put them in the bigger pot.

If you don't want to disturb the roots, and you don't want two plants in one pot, then you could always cull one plant. However, I don't recommend that, as it's a waste of a good plant. What you can do instead is get some scissors and cut one plant off just below the soil level (so you get some roots on it, but you don't disturb the roots of the other plant at all). Even one root makes a big difference (although it's not hard to root cuttings from scratch). Then you can transplant the plant you cut off, and have an undisturbed plant, too.

Tomatoes aren't as bothered by disturbed roots as many other plants are. Just make sure it's not super sunny while you're doing it. Sun can wither, stunt and/or kill plants with disturbed roots.

Keep nitrogen fertilizer away from recovering plants until they've fully recovered. Excess nitrogen increases the symptoms of transplant shock, and it's not good for the roots.


Consider you may be looking at two suckers (actual name) from the same root ball, if they're growing right next to rack other.

I wouldn't break apart the root ball at all. The primary benefit to buying peat potted tomato plants in Spring is the healthy, perlite-heavy root ball.

If there's a straggler distant from the main shoot(s), pull it. Otherwise, bury the plant almost completely in its new pot and prune accordingly later.


Such a wonderful environment for tomatoes. I'd plant the paired tomatoes together in their new pot. Going from 4" to 18" pots isn't a good idea. I'd go to 6" pots, then 10" and then to 18" adding new potting soil each transplant or 'uppotting'. Tomatoes are very sensitive to too much soil in their pots...not enough root mass to suck up the water. Make sure you use sterilized potting soil when planting in pots or containers. Especially Tomatoes, eggplant, potatoes and peppers. Just one errant spore of late blight will kill your entire crop. It is a very disheartening ordeal. Never use anything that you know not where it is from or if it has been tested. I'd use Osmocote 14-14-14 if you've no experience with fertilizing. Don't be afraid to remove leaves that aren't getting sun and when too many leaves get congested enough to inhibit air flow. Always use scissors or pruners cleaned with alcohol. Keep your smoking friends AWAY from your plants!! No touching at all by smokers. Mosaic virus from tobacco is a big big deal. Water deeply and allow to dry out before watering again. Fertilizing with Osmocote will be a one time thing. Too much nitrogen, you will not get tomatoes or reproductive growth, just lots of leaves. Pots have to have drainage holes, bottom of pot lifted from surface and no gravel/rock/pebbles or packing peanuts below the soil and bottom of pot!! I always use fans for the best protection from fungus. Are your tomatoes determinate (bush) or indeterminate (vine)? What variety? Are they non-GMO? I am sure you'll have more questions other than separating starts grown in some nursery and sold in some store! Tomatoes are one of the most important crops individuals can learn to grow...and preserve (drying is best, my opinion).

  • 2
    There are no GMO tomatoes. The only GM Tomato that was ever approved was the Flavr Savr Tomato, which was a commercial failure. They were last cultivated in 1997. forbes.com/sites/kavinsenapathy/2016/12/28/… en.wikipedia.org/wiki/Flavr_Savr
    – GardenerJ
    Commented Mar 3, 2017 at 13:06
  • Ah, the Pomato was a Graft: en.wikipedia.org/wiki/Pomato Not GM or a cross. Commented Mar 3, 2017 at 15:57
  • I don't understand why you recommend re-potting every few weeks, it seems as though that would stress the plants and slow their growth. This is a food crop that will go from seedling to end of season (due to heat and humidity) in about 4 months.
    – Debbie M.
    Commented Mar 3, 2017 at 16:36
  • I recommend re-potting as the plant fills the pot with roots because this only enhances their growth. Stress to a certain extent is good for plants (and us humans). Planting a tiny plant in a big pot is truly a big no-no. Planting a tiny plant in the garden soil is an entirely different concept. Up potting is what any experienced gardener knows and expects and does...every season all season. No matter food crop or ornamental. Ask me more questions as this could get quite lengthy and you sound as if you know a thing or two already! Thanks, Debbie!
    – stormy
    Commented Mar 3, 2017 at 18:22
  • The potting soil I have tried does't work well for me. It doesn't hold enough moisture to make it through a 110+ degree days on one watering. My big pots are filled with a mix of clay soil (from my back yard), garden soil (sold in a bag from home improvement store) and composted mulch (also from home improvement store).
    – Debbie M.
    Commented Mar 4, 2017 at 19:56

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