For the last 4 years, we have had three tender/semi-tender passion
flowers in large pots in our conservatory. All three are vigorous,
producing plenty of leaves and vines.

The conservatory is not heated but faces SW and gets plenty of sun. It's
against the house on 2 sides, so the temperature never drops to lower
than ~5 deg C. In summer, it can get very hot.

Two ('Incense' and racemosa(?)) flower well. The third, alata (?) -
large, unlobed leaves, square section vines with distinct ridges along
the corners, still shows no signs of flowering after 4 years.

The two that flower well tend to drop a large proportion of their leaves
during the winter but shoot again in spring without any problem, going
on to flower well. Alata holds on to most of its leaves.

Any suggestions on getting the non-flowering plant to flower?
--
Larry Stoter

In article , says...
For the last 4 years, we have had three tender/semi-tender passion
flowers in large pots in our conservatory. All three are vigorous,
producing plenty of leaves and vines.

The conservatory is not heated but faces SW and gets plenty of sun. It's
against the house on 2 sides, so the temperature never drops to lower
than ~5 deg C. In summer, it can get very hot.

Two ('Incense' and racemosa(?)) flower well. The third, alata (?) -
large, unlobed leaves, square section vines with distinct ridges along
the corners, still shows no signs of flowering after 4 years.

The two that flower well tend to drop a large proportion of their leaves
during the winter but shoot again in spring without any problem, going
on to flower well. Alata holds on to most of its leaves.

Any suggestions on getting the non-flowering plant to flower?

They can be temperamental! it can often be temperature related, too
higher a summer temperature being the most common problem, followed by
length of growing season, but some sorts need a minimum winter
temperature to initiate flower buds (I had not thought Alata was one of
them) then there is the old favourite - too much nitrogen.
Try contacting www.passionflow.co.uk a number of passion flowers in this
group are closely related and easily confused Myles should be able to
sort you out
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea