propagate trumpet vine

can I propagate it from cuttings by rooting them in water first or putting (0.1 % IBA)rooting powder on them and sticking cuttings back in soil?

Doug says this is a bit of a weed. Easy from seed - in fact it will self sow around your garden very quickly once established and flowering. Tender tip cuttings work well but sticking them back in the garden isn't going to work. They do need some warmth and moisture loss control as per guidelins for cuttings.

Me? I'd wait for seedlings and then try to stop it growing too darn much. :-)