I would like to plant an annual under our front window, which is on
the west side. As such, it is getting shaded from the direct sun in the
morning until about Noon. Then it gets direct sun until about 45
minutes before sunset. In the summer, it will probably be getting about
9 hours of sun a day. With brick up against the back, it can cause a
little bit of a heat island if there is no breeze.

The only stipulation my wife has is that she would like it to have
purple (aka grape) colored flowers. At first I thought she meant dark
red or burgundy, but she does not like those shades. I would prefer
something that has a long flowering season, can tolerate heat, doesn't
need watered 3x a week, and preferably not needing deadheaded all the time.

The lower sill of the window is about 44" above the ground there, so
I could have a row of something taller in the back, and something
shorter in front. The area we have to work with is 31" wide, from the
side of our house out to the edge of the sidewalk, and maybe 12' long.
This will be the most visible area that people see if they walk to our
front door, and I sort of feel like I have to make up for the onions I
planted out by the mailbox.

Any suggestions? Thank you so much!