Seedlings whether grown indoors or outdoors are transplanted usually when they have produced the first set of true leaves. The time it takes for this is not relative. The reason most tomato seeds are started indoors is to get them started before the outdoor climate will allow. If you can start them outdoors you will not need to transplant them if started where they are to grow. Transplanting will usually slow the normal growth by about two weeks. Al

Tomato seedlings can be started indoors 6-8 weeks before planting out. Many tomato growers prefer to "pot up" their seedlings once or twice before finally transplanting them into the ground. Each time you pot up, you bury most of the stem. New roots will develop from the buried stem with the goal of a deeper root system that is better capable of sustaining the plant.

Tomato seeds can also be grown directly outdoors. There is not a hard and fast rule. I prefer giving them a head start indoors.

We use to sow tomato seeds at one end of a tobacco bed, usually in early March. The beds were covered with a cotton canvas until it was time to harden them off. We transplanted them about the third week of May but they were usually ready a week or two earlier, depending on the weather.

Mike

Well see I realize that if I direct sow them where they're to grow, I won't need to transplant.

However when I asked how many seeds were in one disc, the people at the hardware store told me 20. So I won't be able to sow individually where they're to grow via direct sowing.

I'll have tons of seedlings popping up in one pot once they germinate. I'll have to thin them; however the seed packet says that once they have 2-3 leaves some of those seedlings can be transplanted.

When the seedling has 2-3 leaves, after it has germinated and grown some, are these the true leaves (this is basically a few weeks after it has germinated, 2-3)

That's why I'm asking about the age question of the seedling. I don't want to transplant it when it's too young, and it's root system isn't developed enough to
transplant.

Why did you plant all the seeds if you don't want that many plants so have to thin them? You could have saved the extra seeds for next year. I usually get germination rates of 80% to 100%, so would be wasting a lot of seeds if I thinned plants. Plus I can't see killing a perfectly good seedling.

To answer your question about the age to transplant seedlings.... is anytime you can safely handle your seedlings from it's leaves (not stems). I have trasplanted seedlings 24 hours old, very carefully with a lot of other factors to make it successful but it can be done without negative side effects. I am more concerned with how to handle a young seedling than how developed it's root system is when transplanting so young.

I hope that helps!

Keriann~