Do you have rose stem girdlers there? This happened to some of my climbers last year. I also had a couple die in a similar fashion when it rained a lot and the soil was too heavy for the root system. I think they suffocated. I changed my mix this year and it seem much better.

Phuong coi thử trong ruột cây có bị sâu không nhé. Năm nay chị phải cắt sát gốc tới 90% vườn của chị vì bị giống giống em. Chắc vườn chị bị từ xuân trước nhưng vì chị không có kinh nghiệm nên nuôi sâu cả năm. Những cành non mập sẽ héo nhanh nhưng cành già cứ sống bình thường nên chị không biết. Cây vẫn tốt nhưng ít hoa hoặc nhỏ hơn bình thường. Tẻ cành ra thì chỗ có con sâu, chỗ đã bị rỗng đen hoặc bắt đầu bị nâu ruột. Chị sởn hết mấy trăm gốc. Đau lòng gần chết vì nhiều cây leo 7,8 tuổi cũng bị cắt. Chị biết em rành về hoa hơn chị nhưng vẫn muốn chia sẻ hy vọng có thể giúp em. Thanh

Downey Mildew took one of my roses down suddenly. I hear it is weather related and my plant was struck it's first wet Fall. Thankfully, no others got the affliction.

Do you have a photo of what it looks like when the leaves & branch start to die?

This happens to me in South Florida, and honestly I think it’s just the constant heat getting to them. Make sure that in the hottest months they either get some shade, or at the very least, try to keep the roots cool by mulching the soil in the pots. Try putting them in only morning sun for 4-5 hours and see if that helps. Sometimes roses can’t take full sun all day when in pots. It heats up the roots too much.

Also, what kind of pots are they in? Roses in hot climates do better in clay, unglazed pots, but those also dry out faster so you’ll need to water more often.

Lastly, try putting the pots up on stands so they are not on the hot concrete floor. This helps keep them cool.

And one more tip. How often are you fertilizing? In hot weather roses can grow faster and need more fertilizer than normal. Liquid feed is best in the hot weather.

Good luck.