Can I plant the whole egg carton in the ground when the seed finally germinates?

Yes, the carboard-type egg cartons will decompose in a few weeks if they are undergound. I put them in my compost pile all the time. The styrofoam-type won't decompose, of course.

If the plants really are ready to go in the ground weather-wise, I would thoroughly wet the carton and poke several holes, slice the sides with a utility knife, and even completely cut out the bottom before you plant them. Be careful not to touch any roots while you're cutting. This will make sure it drains well and the roots have a way out.

Same goes for those peat pots they sell starter veggies in.

Planting Seeds In Egg Cartons

As already mentioned the paper egg carton will eventually decompose but the seedling may suffer before that happens. A better idea than cutting off the bottom of the carton pocket is to soak it in water for a few hours until it is very soft, then carefully peel it away from the roots of the plant. If the seedlings have been left too long in the carton the roots will start to penetrate the cardboard and it is almost impossible to get them loose. Even if you get all the soil and root ball out in one piece you will leave vital roots behind. Cutting the carton will invariably cut some roots off as well.

You could plant them, but it is not the best answer. Tiny plants will struggle until the cardboard decomposes. The plants will be too close together, not enough room to grow properly.

It is easy to learn how to remove baby plants from the cartons. Do not pull the plant out by the stem. Squeeze the carton a few times from all sides to loosen the dirt. Then gently remove both the dirt and plant together. If the roots of two plants are mingled, wiggle them gently apart.

Use any good potting soil. Press the soil into each of the little compartments in the egg carton. Punch a very small hole for drainage in the bottom of each compartment. Then press a seed into each little compartment. The main problem with this method is that the little containers are very small and shallow, so you will have to transplant the seedlings (to larger containers or the ground) almost immediately after they sprout. You could plant grapefruit or lemon seeds in this way. But citrus fruits such as grapefruit or lemon do not "come true" from seeds. That is, seeds from a good variety of citrus fruit will not make plants having the same characteristics as the parent tree, or fruit like the fruit the seed came from. Commercially grown citrus trees have shoots from known desirable varieties grafted onto disease-resistant rootstocks.

you can but its not a great idea the roots will want to get into the dirt you might have some wilited plants befor they finaly break though the carton would cut he bottom off the carton then plant or you can just take the plant out and put it into the dirt

get a knife and cut the sides of pocket of the egg carton