Answer: The most common reasons for lack of bloom on trumpet vine (Campsis radicans) are lack of sun and pruning at the wrong time. Your plant should be receiving enough sun on the west side as long as it is getting full direct sun all afternoon. This vine blooms on new growth of the season, so pruning in summer will reduce or stop flowering. The best time to prune it back is in late winter to very early spring. This stimulates vigorous new growth and also consequently blooms.
I would suggest that you try giving the vine some good quality compost as a top dressing in fall and spring, fertilize with a complete granular or slow release fertilizer in the spring (follow label instructions), and trim it back very hard this spring. You might also try a deep watering once a month to encourage strong growth.
I hope this helps.
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