I purchased a pot from lowes... probably a 2 gallon. It has 3 clematis in it, the president, henryi and violet charm. they have multiple stems and have already wrapped themselves around the trellis a few times. I removed them from the pot to plant in the ground and they were extremely root bound. I dug a whole probably 15 inches or so wide and 1 ft deep and put them in it. Should I have tried to cut them back and devide and separate them further apart. They were planted very close in the pot and are impossible to untangle from the trellis. . Thanks for any info!

tink

Sounds like you found a good deal. The hole is small for even one clem. If you want to separate them you will have to sacrifice the blooms this spring and cut back the growth to about 12 inches. Do you think you can untangle the roots? Or you can probably dig it back up in the fall to trim and untangle if you keep it mulched and watered. Generally, the hole should be atleast 18 x18 and amended with compost

Welcome, Tinkster.

Anna gave ideal advice. I'd wait to cut them back and separate them until late fall. Where do you and the clematises live?
Holes 18" x 18" for each clematis and using compost and bone meal will help the plants to live. Regardless of your growing zone, I'd mulch very heavily for the winter.