My trumpet vine didn’t bloom this year. I have two different varieties in my yard and they are both probably over 15 years old. They did have leaves but no flowers. I know it was very hot & dry here in Michigan this year. Is that possibly the reason? They still are magnificent but the hummingbirds were so disappointed this year!
would look more to a fertilizer, or pH issue! Dolomitic lime, and and all purpose fertilizer will help condition your soil back to where it needs to be.
Here is an article for more information on care of the trumpet vine: https://www.gardeningknowhow.com/ornamental/vines/trumpet-vine/growing-trumpet-vines.htm