Purchased one of these beauties in June. Planted it in a pot on my porch. It was about one foot high at the time. Since then it has grown to about 15 feet and is growing strong along a trellis. However, there are no flower buds. I’m in zone 5B. It gets less than the recommended amount of sun ( only 1.5 hours direct) but gets indirect all day. I’m wondering if it won’t flower at all because of lack of full sun OR is its vigorous vine growth a sign that it’s OK. When should I expect flowers?