Does A Dipladenia Die Off At A Certain Age?

Question

I live in South Africa and always have 3 dipladenias in large pots on my terrace. While 2 flourish the third often shrivels and dies. Do they only have a certain lifespan?

Answer 1

My research showed they are perennial in warm climates such as yours. So, no, I wouldn't say they had a short lifespan like annuals. Perhaps the third plant succumbed to disease or insect invasion. Sometimes identical plants only a foot apart will perform differently. Does the third one get more shade perhaps than the others? Does it have a larger pot that may be causing more moisture retention leading to root rot?

Here is care information.

https://www.gardeningknowhow.com/ornamental/vines/mandevilla/growing-a-dipladenia.htm