Problem With Plumbago! Please Help

Question

Dear Gaerdening Knowhow, I wish to ask for your help. My outdoor, container-based plumbago (plumbago auriculata, cape leadwort) is finally growing well but still shows signs of problems. I have just re-potted it in acidic soil and added 10% sand to help with drainage, as I know that’s important. I think I had been over-watering so now only watering once per week. It’s quite hot and dry now (I live in Madrid, USDA Zone 9a) so I wonder if I should water it more. I have two queries and I’d be very grateful for your help! Firstly, new leaves are sometimes shrivelling and turning completely brown, like in first photo. What could be causing this? Secondly, there seems to be a fine white powder gathering on some of the leaves, like in second photo. Is this normal or could it be some kind of bacterial infection? The third photo is of the whole plant in its container… Once again, thanks so much for any help!

Answer 1

Unfortunately, none of the photos came through. I am unable to see the damage. Without treatment, bacterial infection from overwatering will carry over to the new soil.

It sounds like multiple infections. It would be hard to say which without seeing the damage, though. Fungicides will take care of the issue. This article will help:

https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm

This article will help you to care for Plumbago, properly:

https://www.gardeningknowhow.com/ornamental/shrubs/plumbago/growing-plumbago-plants.htm