I like the trellis to hide as much as possible but I would not spend much money as it is best spent on new siding.

I really like the trellis idea. If the cost of the trellis is too much $$, perhaps buy the square trellis and put a frame around it. or make on yourself. Remember to power-wash your siding before adding the trellis.

Use landscaping. A well-placed tree or two in your yard will draw attention aay from the wall.

Window boxes require constant watering, sometimes twice a day. You are frequently replacing the plants in them as they die or just start looking tired and ratty. Expensive and time consuming.

I am an enthusiastic gardener with a green thumb and I won't have them ever again.

They also stain the siding under them.