hi, not only does the taller container give more room for roots to grow deep but since tomatoes sprout roots all along the stem below ground the ones in taller containers have much bigger root systems.

Thanks for the interesting comparison.

Some say the very act of transplanting/potting-up stimulates the root systems causing increased growth.

John

There is also another even more improtant reason why the growth of them is different. The taller cup is more slender.

Often when one transplants to a pot that is too large relative to seedling size the growth slows.

Here is why

One of the key things for roots is oxygen. Roots require oxygen. More oxygen tends to be at the sides of the container (also depends on mix used and how moist it's kept). Roots that can reach those sides sooner often result in more growth. There is also probably a benefit of water (and fertilizer) coming in more contact in that area. Still oxygen is key.

This holds true for many bedding plants when transplanting into containers where they will not "finish" grwoth.

Here is a link that might be useful: Here's a link that will definitely help

I agree that potting up sooner rather than later helps tremendously. I have 5 Cherry tomato seedlings in 16 oz plastic cups started from seed one week after my other tomato (and some pepper) plants that are twice as big because the other plants are still in Jiffy peat pots (until I get home today!). =)

Oxygen is key as mulio states. I pot to 16 oz. plastic cups and puncture holes along and up the sides. I put holes in the bottom , but anymore only for air. Drenching soil to the point of saturation at very small seedling time can get you in big trouble.
Some use the method of potting to progressive sized pots more than once, but...... I believe the concensus of professional growers is one pot up to 6", obtains the best results for them..

Wish the link was still available, I would play it to the plants:)

Any stimulation of the root system, will cause more development. There is a thread in FAQ about root development. It was posted by one of the leading midwest tomato experts.....hortist.

When the tap is broken, or damaged, along with any formed laterals, it causes even more laterals to shoot out resulting in the fiberous, dense mass of roots that are desirable to sustain the plant in the best of conditions for the stresses and energy needed later.

Tom

Drenching soil to the point of saturation at very small seedling time can get you in big trouble.
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Tom,

Just how do you water at this stage?

Just give them a small sip?

John

I noticed quite a boost in growth in both my tomatoes, but especially my eggplants. 6 days after the pot up they had doubled in size.

mr potato head, what size cups are those? 16oz?

Windclimber-

Mulio IS hortist.

jaime-

The tall cups are 24 oz. The shorter ones are about 22 oz.

John,............ I use a commercial potting, moisture control soil........pouring the whole bag out and mix w/ water infused with Superthrive, just enough to be able to squeeze a drop or two out by making a fist. About a week later you may need a turkey baster shot of H2O if the soil is crusty.

I cold treat them and with the weather the way it is warm here lately, it's more of a 55-60 degree treatment, so the soil drys a little, and the plants are going strong, rather then a bit muted, so the roots develop ahead of the tops.

cindy, I can't kid you...............Mr.K and I go back a few.

I have also found that when I pot up to different sized pots, those in the larger pots grow significantly faster. In fact, I usually put two plants in the larger (i.e. 5x5 inch) pots, and both of those will be about 30% larger than the individual plants put into 3.5x3.5 inch pots. This year the little guys will all be going right into 8 inch round pots 1/2 full of soil, and I will add soil as the plant grows. I know several arguments against this, but (a) have not seen any evidence that they are in fact accurate, and (b) I will try a few test plants with other methods and see how they do.

Anyone who doesn't think potting up or even potting up early isn't worth it or has no importance, check out this post.

Ok, here are the pictures, after transplanting what I had enough soil for, to 16 oz plastic cups. I also did some labelling. :) Still not good enough though, as I lost track of a few of my pellets (Jalapeno's? maybe...Serrano's? maybe). Anyways, I feel better now knowing that all of my tomatoes are in bigger cups. The first picture is a few of my Cherry Tomatoes, started on March 10th. The second picture is my remaining seedlings (all about 1 & 1/2 to 3 inches) planted a week earlier (yes) on March 3rd. Potting up early makes sooooo much of a difference!...

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I'm not going to refute the importance of potting up; in fact I endorse it fully. However what Mr Potatohead is demonstrating is anything but...

What you have clearly demonstrated is a difference in drainage between two types of containers. To easily make a visual reproduction just stick a sponge in water and then lift it up with the largest surface down. Allow it to fully drain, then turn it onto its edge and watch all the extra water pour out. Your soil is very much like a sponge.

What you need to do if you are going to use homemade containers is punch the bottoms full of drainage holes. You may even need a better draining media.

There are holes in the bottom of all my cups. See the papertowels below them? =)

ALL of my cups have FIVE holes punched in the bottom with the tip of a pencil.