Tiny round Peat Pots Are The Next Step Up From Cell Starters Or You Could Start Seeds In These. Pot may be planted in the ground and will biodegrade with roots expanding beyond the original peat pot or may not. Here's the thing, if the peat pot is dry the roots will not go through. Then you should take the plant out of the pot to plant it. If the peat pot is kept moist and the roots are starting to pass through then you can plant the whole pot and the roots will expand. However, I would still cut the bottom out of the pot to allow for greater expansion.