Answer: Many vines require two to three years to settle in and become rooted and established and bloom their best.
Trumpet vines will perform best if planted in full sun with average soil. If your vine is in the shade, it will not bloom well.
Overfertilizing can cause them to grow more foliage at the expense of flowers, so make sure you are not oversupplying it with nitrogen. For example, if it is adjacent to a lawn that is being fertilized regularly, you would not need to fertilize the vine in addition to the lawn.
Also, this vine blooms on new growth of the season, so make sure you are not pruning it during the summer. Many gardeners cut it back hard in late winter to early spring each year. This encourages vigorous new growth and more blooms later in the summer. Trumpet vines usually begin blooming in mid summer.
I hope this helps.
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