I have 25 seed grown babies, almost a year old, 6 purchased seedlings 2 years old, and 6 purchased plants 3 years old. I want to try putting the 3year olds outside for the summer. Will an umbrella be sufficient shade to acclimatize them to full Sun? I live in Ontario not far from Toronto. Here are pics of my adenium family from youngest to oldest which are the subject of my question.

An umbrella should provide sufficient shade .... or - the north side of dwelling, along a east or west facing wall, or under a tree or shrub will work too ...

to leave them out ...wait until night-time low temps are a steady 50° / 10° (F / C) ....