To keep in the pot or bury in the ground?

rockm

Buring the pot with the plant in it complicates things greatly and has no real advantage. It may hinder the plant to the point of making the whole exercise pointless.

Burying the pot defeats its drainage capabilities, since the drainage holes will most likely be plugged by the surrounding soil. On top of that, you have gained none of the advantage you're looking for by planting in the ground in the first place. The plant is still in the pot and will be for some time, until the roots rot over winter from the excess moisture, they girdle the main plant over a couple of years, or until the roots find the drainage holes and grow out of them. Once freed, those roots might make something of the plant, but all this is very iffy. You can avoid all of it by simply removing the plant from the pot and putting it in the ground.

All of this is beside the point, however, if you live in an area where your local climate doesn't match the plants you're working with. Rosemary isn't going to survive a New Hampshire winter. A larger pot (but not too large) would work better in thickening it up. The azalea is iffy. The Japanese Andromeda won't fare very well with constantly wet feet.