Q.Trumpet vine
My Good friend gave me three pieces of trumpet vine with the roots she dug up. She placed them in a bag with a root growth hormone for me to take home. Once I got home I planted two of them in a pot with organic black soil mixed with some of my compost. The third I removed the two lowest leaves and placed in a pail of rain water. They were all looking good but now it’s been about five days and all the plants have drooping leaves. What can I do to save them? I have them in a shady area and the ones in soil I make sure the soil is moist. These are from a well established plant.
Your on the right track, but I would cut the 'cuttings' down to a shorter length. This is much easier to root then a long cutting. I would make the cuttings about 3 to 4 inches in length.
Just cut the branches down to about 3 inches above the soil and try to leave 1 set of leaves above the soil. Make sure the soil is moist but never soggy.
Here is a an article with more information.
https://www.gardeningknowhow.com/ornamental/vines/trumpet-vine/propagate-trumpet-vine.htm