Hello, I am in Toronto and my question is:
Can mounding dipladenia withstand hot afternoon sun? I’ve planted there Non-stop begonia and their leaves were scorched. I had to move them quickly. I like dipladenia. Can it tolerate that situation? Soil is rich and water can be adjusted.
Dipladenia is actually a member of the mandevilla family. Many people think that mandevilla and dipladenia are the same plant, but while similar, dipladenia foliage is somewhat smaller and the plant is more shrub-like, while the mandevilla plant has a vine-like growing habit. Both these plants enjoy the heat and flower best in full sun. I think dipladenia will do well in the situation you describe with full sun in the afternoon. They will tolerate some dryness and continue to flower, however they prefer a consistent level of moisture and you should try to keep the soil damp, not wet. Dipladenia are not hardy in Ontario and will need to be overwintered indoors.