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What happen to ROOT BOUND tomato plants?

Irving, TX(Zone 8a)

My tomatoes are growing too fast and to good this year.
I finally found the best light and media to grow them.
They are in a 4" pot and I found out that I have many roots on the outside edges of the pot.
I know that I need to pot them in a larger size pot ... but will it happen if I don't?
I am hoping to be able to plant them outside in 3-4 weeks.

Any help?

Lilburn, GA

repot into bigger pot now. Plant out in 3to 4 weeks if danger of frost ha

Repot now and plant out in 3 to 4 weeks if danger of frost has past

Charlotte, NC(Zone 7b)

drthor - if your plants are "root bound" when you set them out in the garden, you will have to cut some of the roots away or the plant will not do as well as if it were not root bound. This means your plants will have to regrow those roots.

It's much better if you keep "potting up" - once the roots touch the walls of your pots - move the plants to larger pots.

Of course, if you don't have room indoors for all those larger pots, you're kinda stuck between a rock and a hard place!

Efland, NC(Zone 7a)

Thor, if you need to you can repot them right back into your 4" pots by pulling them out, trimming some roots, setting them deeper in the pot, then adding your soil. This can be done by laying the root system at an angle and gently swirling the stem of the plant into a circle; gently.

In addition, put them in a much cooler room. If those are in the same room with your pepper and eggplants that room is too hot; the tomatoes will do much better, and grow slower, at a cooler temp (and eventually give you more production as well).

I'd do this especially if you have any cherry varieties as they'll grow much faster than standard tomatoes. On an even better note, the cherries will easily take root pruning/repotting/etc and bounce right back. (It's the caveman in them!)

"I know that I need to pot them in a larger size pot ... but will it happen if I don't?"

The plants could end up with a much slower growth once planted out, delayed harvest, and exhibit weak top growth until the root system can regroup and support new growth in a healthy manner.

But I wonder, just because you have "roots on the outside edges of the pots" doesn't necessarily mean they are root bound. I'd watch for them to start circling/girdling the pot and also turning from a nice healthy white color to yellowish/orange. That would be the stage of root bound you'd be most worried about.


Salem, NY(Zone 4b)

I agree with Shoe and will add a bit more.

I used to grow all my plants, after the initial transplant, in 2 inch cells in a tray that held 32 cells and I grew them to transplant size of 6-9 inches in those same pots, and it may surprise some of you but I WANT the plants to be rootbound when I set them out.

Rootbound plants transplant well as opposed to plants that have been potted up to encourage more growth b'c those develop a huge fibrous root structures that are very fragile and so doesn't transplant as well b/c they fragment apart.

More to the point, there were seasons when I couldn't set out the plants when they should have gone out, b/c of weather, and it was my farmer friend Charlie who told me what to do.

Strip off all foliage leaving just the leader stem with a tuft of foliage at the top. That cuts down on photosynthesis which is necessary for growth. And then put those plants in a very cool area and out of the sun and not under lights.

I admit that those stripped plants look awful, but once planted out, and sometimes I had to trench them b'c they were so tall, they took off and made fine plants.

So that's my experience with plants that grew too big too fast.


Irving, TX(Zone 8a)

Thanks so much for all your help. I didn't expect my tomatoes to grow so fast and so big in such a short time.
But I am happy that I "FINALLY" have found the right light and soil mix.
I am planning to repot my tomatoes this weekend in larger 6" pots.
I am also putting them under a different light and in a cooler place.
The roots don't come out from the pot yet, they are just around the edges.
I really appreciate y'all help. Sincerly

Thumbnail by drthor
Central, TX(Zone 8b)

Do tell - what mix and lights are you using?

Your predicament is exactly why I don't seed maters (indoors) too early! I've just seeded mine (community pots, heat mats & full spectrum sunlight T-12's). After they're up with 2-3 true leaves I'll transplant them into deep styrofoam coffee cups to grow on under cooler conditions until I can set them out in the garden beds with protection.

I'm also experimenting with homemade newspaper paper pots; they last 5-6 weeks and work just fine with roots easily penetrating the moist paper - just like peat pots, when setting them out don't let the paper extend above the soil line.

Ms. Tommie

SE Houston (Hobby), TX(Zone 9a)

This morning, I performed surgery on a number of seedlings whose seed pot was holding them captive. I noticed I have one set of true leaves growing on a number mighty sturdy looking seedlings. Today is day number 11 since I sowed the seeds.

The seedlings are growing in a community plot, and not all have a set of true leaves yet.

Should I wait for a 2nd set of true leaves on the dashers, so the laggers can catch up with at least one set of true leaves, before I disturb the plot to start potting them up?

?? thanks!

Central, TX(Zone 8b)

Gymgirl...guess it depends on how many dashers you have now and how many plants you really need.
If they're packed too densely the lagers may never catch up due to competition by the stronger seedlings and if you wait too long the root systems will tangle!

I tend to plant mine in community flats, spaced in rows (labeled by variety). It makes lifting a few stronger seedlings easier while allowing the lagers to keep growing without disturbance. Just fill in the vacant spots with moist, clean seedling mix.

Ms. Tommie

SE Houston (Hobby), TX(Zone 9a)

Thanks, Ms. Tommie.

QUESTION: I see I have some small patches of white mold forming on the top of the seedling mix. I'm going to cut back on watering until it's critical, to allow the soil to dry out a bit. Also, I'm familiar with using peroxide in the past to handle this problem, and my intent is to go home and lightly mist the soil with a solution of 1 tbsp peroxide to a gallon of water. I don't need damping off at this point.

What do you think? Do you have another suggestion? Thanks!


Salem, NY(Zone 4b)

Linda, the white fungi that you see on the top of the mix is not a problem for the tomato plants but everyone I know wants to get rid of it and I did too many years ago when I foolishly used peat pots.

just scrape it off and discard a thin layer of mix with it. That's what many others do as well although I do know some who use peroxide, which I don't think is necessary.

Whether removing it by scraping it off or trying to kill it with peroxide there's nothing that says it won't come back if spores have already been formed.

That white fungi is from just normal spores in the environment and is not one of the ones that can cause damping off of which there are three different genera and species, but not the normal saprophytes that are in the air.


SE Houston (Hobby), TX(Zone 9a)

Thank You, Dr. C!

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