So today's 85 degree heat has made quite an effect on the primrose. It amazes me how fast heat affects plants and how fast water and shade revive them. Half an hour and a quart of water later one of the leaves was back up to vertical.
I was lucky to catch it before it really got bad.
Later in the evening when the sun had gone around to the other side of the house the plant was nearly back to normal.
Most plants can't survive numerous days in a row of such extremes, so I have pulled the plant out of the path of the sun and given it a shade cover until I can find a better permanent location. The extreme heat that is reflected from a solid patio is part of the reason that I want to preserve some kind of grass or ground cover for a majority of the space rather than paving or gravel like many of my neighbors have. If you have ever stood on a patio and felt like the poor little plant that wilted, you know why the heat island effect causes such weather differences between the city and the country.