in USDA zone 8b (Tucson), I planted yellow orchid vine (callaeum macropterum) 1 yr ago in well-drained soil on trellis (facing east-west) b/t single-storey houses only 8' apart; it gets 4-6 hrs sun daily thruout yr. Watered weekly in winter, 2x wkly in summer, very regularly.
It thrived for entire year, until 4 wks ago it began to wilt, dry up. Only a few yellow leaves. No grub worms found in soil underneath, nothing on leaves. Regular watering had no effect. Now seems near dead.
ALSO: Same vine on another wall nearby gets a bit more sun, got same treatment for same year, now also starting to wilt, both leaves and flowers.
This is a hardy vine I'd like to keep, but am clueless about this apparent die-off.
Any suggestions welcome.