I planted these at either end of a pergola. They grew profusely for 15 months but now both appear to have died. I am in zone 9/10 Florida and though have had some cold weather this winter no frost. I have only bare woody stems along top of pergola with minimal green on PSJ only. Blue pea looks dead. Will pruning help these vines to recover. If so ,how much
Port st John and Blue pea vines
From what I've read, the blue pea vine should come back from the roots. Look for new growth around the bottom. We grow it as an annual further north and it sprouts quickly from seed.
The Port St. John creeper also sprouts from the roots when knocked back by frost as well gardeners even in zone 8 report success with it.
On either of these vines, a good trimming will probably help. Cut back one leader as an experiment. If you see green, then the vine stem is alive and should re-sprout leaves.
Since you are in South Florida, I think it's safe for you to prune your vines now if you haven't done so already. I'm pretty sure we won't be having anymore extreme drop in temp's. I don't grow the Port St. John Creeper but I have the Blue Pea Vine. I live in the northern part of the state and my Blue Pea hasn't shown any signs of regrowth yet this spring. I cut it back almost to the soil line a couple of weeks ago. The woody vines were totally dry and dead so it may have been killed by the freezes this winter. I saved seeds just in case. :)
"Port St. John's Creeper" - Podranea ricasoliana:
http://davesgarden.com/guides/pf/go/1755/
http://www.plantzafrica.com/plantnop/podranricasol.htm
"Blue Pea Vine" - Clitorea tineata:
http://davesgarden.com/guides/pf/go/528/
Many thanks for these replies. PSJ has been severely pruned bur remaining stems are growing vigorously. Blue pea has been cut back to ground but no sign yet of any growth. I planted some seeds in pot just in case !