"........I am about to make my first foray into Morning Glories. The seed
packet says they can be directly seeded, if they put in warm water
overnight. I'm assuming this means start them out in warm water and let them
stay at room temperature the rest of the night.........."

I find with hard coated seed that if you put them into hot water that you
can only just put your hand into, and leave them there till the water goes
cold then they will have taken up sufficient water to start growth.
What happens is that the hot water expands the air inside the seed coat (if
you look closely you will see small bubbles) then as the water cools then
the remaining air contracts and draws in water.
With very heavy seed coat or shell then I use almost boiling water.
If you have seed that is floating after one dose of this then a second go
with slightly hotter water normally works.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk