Why vines didn't flower?
On May 9, I planted fresh seeds in nice potting soil for Moonflower vine and Spanish Flag vine. What could be easier? I had BEAUTIFUL, healthy vines and leaves and they climbed and climbed but never had any flowers. I fertilized perhaps once or twice thru out the summer. Watered a lot. Any idea why no flowers?
Marion County Oregon
Ipomoea don't like wet roots. They would prefer to be moist but too much or too little watering could set blooming back. Both the Spanish Flag and Moonflower should do well in sun, though the Spanish Flag will do sun or part shade. Since you indicated there was plenty of foliage growth I wonder if they were getting too much nitrogen but maybe not enough phosphorus to support flowering. Check the ingredients in your fertilizer and potting soil for the chemical content. Many fertilizers are specialized for plant growth, or for flowering/fruiting.