Here you go:

Growing from Seed FAQs

Ok my seedlings are growing. Now what do I do FAQ

Hardening off seedlings FAQ

Best containers for starting seeds FAQ

How to get started growing from seed FAQ

Do I need a special grow light FAQ

As you'll see 16 oz coffee cups are normally used only after the seeds have germinated and develop their first or second set of true leaves. 16 oz is far too much soil for young seedling as it holds too much moisture and their roots drown. The only way a container that big can work for baby seedlings is if you only fill the cup about 1/4 full of mix (2" or so) and then add more gradually as the plant grows. But that isn't ideal.

You can start seeds in the small 4 oz. or 6 oz 1/2 full cups if you have to use cups and then transplant them to the bigger cups later. Make sure there are drain holes in any containers you use.

Lights must be fluorescent , not incandescent. I don't know what your closet light is.

Very few, if any plants, remain in the container they were started in but there are many variables that can determine that including the type of plant. Most seedlings will benefit from transplanting at least once before going to the garden. The exception is those plants that should be direct seeded to begin with like squash and members of the melon family.

How to grow tomatoes from seed

Dave

Dave,

thank you for your post. Im so glad I included the size!! You saved me from a huge mistake.

what about the K-cups people use to make coffee? Is that enough size until the young shoot beaks to the surface? Or is that too small? How long after that points should I put it in a larger coffee cup?

Sorry but I think those questions were answered above. Did you read through the FAQs I linked? K cups are far too small and when you transplant, as explained in the FAQs is totally dependent on the size of the containers you use. Which is why most use plastic cell packs just like you buy your transplants in from the stores.

As a very general guideline plants can be transplanted to larger containers once they develop their first set of true leaves (see the pictures in the Tomato FAQ) but if you used a bigger container like I mentioned (the 4 oz cups aka Dixie Cups) then they can usually stay in them until they have 2 sets of true leaves.

There are lots of discussions here about when to transplant seedlings and there is a FAQ about it too.

You are getting a late start as it is so why not worry about actually getting some seeds planted, sprouted, and actually growing before you worry about transplanting them, ok?

Dave

Dave has offered you some great advice and links to your 'homework'.

I'm simply going to stress the fact that the primary reason for starting seeds inside is to have some nicely developed plants to put outside as soon as it's safe (frost free) to do so.

That means we all planted our seeds months ago. I'm planting mine today (yay!!); they range from 6"-12" and were started somewhere around two months ago, maybe more.

rhizo raises a good point. You are trying to learn everything about growing from seed now, this late in the seed starting season. Successfully growing from seed has a long learning curve - time, research, and experience are needed. So that should have been a last winter time activity rather than now.

Off season gives us all time to read, do our homework, do research, and accumulate the necessary equipment. That's not really possible to do now with any degree of success. So perhaps you should plan on buying your transplants this year and then spend this coming winter learning all about growing from seed. Just something to consider.

Dave