Q.Can I save my mandevilla bulbs for next season
Can I save my mandevilla bulbs for next season? I live in the northeast. I cut down the plant not realizing they had bulbs or tubers. Can I still save the plant?

Did you leave the bulbs in the pots? This would be the most ideal situation.
Just move the pots into a dark location at temperatures that remain at a constant 40 to 50 degrees.
Keep the soil barely moist.
If you have dug up the bulbs you can also store the bulbs. This is a little bit more difficult and may not have as much success.
Wrap the bulbs in slightly moistened newspaper and put in a dark plastic bag. Store in a cool dark location with constant temps that are between 40 to 50 degrees.
Check the bulbs monthly to make sure they are not drying out, mist the newspaper if needed.
When spring arrives bring out your plants and bulbs.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm