You may be able to get away with just transplanting them to 16 oz cups. They might get a tad rootbound the last week or so, but they should be fine. What stage are they at right now? Did you just today start them from seed? I ask this because 8 weeks from now doesn't seem like what would be the last frost date for any part of Illinois.

- Steve

I should have said "I'm going to...." I haven't yet but was planning on starting the first or second week of March. Thanks for the reply.

I am in IL also. I start mine in clear 16 oz. cups with holes in bottoms the end of Feb. I put in only 2" of soil in the bottom of the cups then press 2-4 seeds in each. Once they are up and growing, I constantly fill up to the top leaves with soil until the soil is up to the top. I get very healthy seedlings this way with roots growing all the way up the stems.

They are root-bound when ready to plant the end of May/first part of June, but take off quickly once in the ground.

If they outgrow the 16-oz cups, you can plant them even deeper in 2-liter soda bottles with the tops removed. If you plant them deep, they'll keep growing the roots you want when you finally set them out in the garden.

what size pot will I ultimately need before putting them in the ground

Average is 4 inch pots. The 16oz cups fall into that range, just deeper.

Dave

So is depth more important than equal volume, given that it seems to be recommended to start burying the stems to add to the root system? In other words, narrow with a 5" depth vs. wider with a 3-4" depth. Thanks for bearing with a newbie.

That is going to depend on how well grown your plants are I think. If they are good short, stocky well developed plants because they have had adequate light, good temp control, proper nutrition, etc. then depth isn't all that important. Won't hurt but isn't required.

But if your seedlings are long and lanky due to inadequate light or warm temps etc. then the extra depth will definitely be needed.

Type of variety ie: bush, indeterminate, determinate, etc. may also play a small role in determining the pot size needed. Cherry types grow fast for example while one of the dwarf varieties won't need all that depth.

Dave

veryzer

I don't know how much either one matters as long as there is sufficient room for root development, while some cramping of the roots themselves does not seem to cause problems at all.

The majority of tomato roots develop naturally in a mostly horizontal direction, though if the taproot is left undisturbed, it will extend quite a way down. But apparently it doesn't have to do that to support a very healthy plant.

When you plant a seedling out in the garden, you can provide for root space by trenching and burying the seedling horizontally up to its upper leaves OR by digging a deep hole and burying it vertically the same way.

What you want to aim for is to provide for a substantial root system while the seedling is in your care. With a good root system, your plant in the garden will be able to thrive under more difficult conditions than with a scrawny set of roots. But tomatoes are like weeds -- past the seedling stage they stand a lot of abuse and still keep on producing.

Great info. Thank you much digdirt and Anney.