Clock vines in pots not blooming

Every year I plant Thunbergia alata in some hanging pots on my front porch, and they usually do pretty well. This year, though, they are growing fine, but I'm getting no blooms. I read that they don't like to bloom in hot, humid weather, which we've had in spades here lately, but the ones growing on strings by the garden shed are blooming away.

I have them planted in that Miracle Gro potting soil mix - the one with the fertilizer mixed in. Seems like I read that if a soil is too rich, you'll get growth but no bloom on some plants? The only other thing I can think of is it is too shady on the porch, but they have bloomed there in years past.

Hmmmmph! Silly clock vines. Just do what you're supposed to do!

I've got a huge grandiflora in a huge pot it's up in the rafters of the greenhouse, and has bloomed one time, with only a few, haven't a clue why it's not blooming, it does get hot in there, but I keep the soil moist.