How do I know when to transplant seedlings to a bigger pot
I recently purchased a 25 pellet Jiffy greenhouse. It's 25 small peat pellets and right now 16 have sprouted up seedlings. The tomato seedlings seem to be growing the quickest--how do I know when to place them in a bigger pot? I don't want to keep the top of the greenhouse on if it's going to be detrimental for the plants already growing. Help!
As soon as the seeds germinate, you should take off the cover, so the seedlings can get plenty of light. You can plant the seedling pots as soon as the seedling has 3-4 true leaves. Here are some articles to help: https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-tomatoes-from-seed.htm