Q.Watering Trailing Lantana In The Summer Months.
hi, This happens every summer. Live in So Cal. About every other day the plant is very limp looks dry to me so I water. I do admit only water the area of the plant. When we do have rain after colder months and leaves are turning black I trim back and in Spring I lift plant and trim out underneath bare lengths. l don’t know if they are called vines. I recently plopped a filled water bottle that I have made holes in top near where I think the roots are between two stakes. It’s gone in a day,ha. Sorry to make this long but trying to add all info. Thank you for you time and information. My camera is still not added to “new” computer.

Certified GKH Gardening Expert
Unfortunately, without photos it is hard to say what is happening. It does sound like they see quite a bit of stress from heat, watering, and transplanting. I would treat with a fungicide, proactively, to mitigate any infections that might take advantage of the situation.
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/special/organic/biofungicide-information.htm
These articles will help you to care for the plant: