Hi Folks - I'm having problems with my Convolvulus Sabatius as parts of them seem to be dying and looking like burnt ash. Up until recently they been flourishing. I've got gardenia growing next to it that seem ok. Wondering whats causing part of the plan to die off like this? Appreciate any input. I've attached a photo so you can see the effect
Unfortunately, your photo is not attached. Convolvulus species are susceptible to fungal infections and I think that this may be your problem. If it is a fungal infection you need to prune off all the infected leaves and stems and place in your garden waste bin not your compost bin. You can spray the leaves with a sulphur based fungicide or organic fungicides composed mainly of Potassium Bicarbonate.
Watering first thing in the morning is recommended - this will allow the leaves to dry out quickly also try to water the soil rather than the leaves.