I haven't used peat pots in years, mainly because of the issues that I had with the roots not being able to grow through them. I would suggest, when planting them out, if you don't remove them from the peat pots, make sure to water them well and at least poke your fingers through the sides and bottoms of the pots to provide openings for the roots, and then, as Stone said, be sure to completely bury the peat pot (don't leave the upper edge sticking up above the soil line).
