I have had this plant for almost a year. When I bought it it was fully open, now it seems to be closing up,
I live in San Mateo California - it gets a lot of sun and fairly mild climate.
Any thoughts I why this is happening. It is not as pretty when it is not fully open.

Thanks,

Sometimes agaves will close like that because of dryness. It may need more water. However, watering them is a tricky proposition. They do not like a lot of watering. If you do choose to water, do so very sparingly.

cookie36!
In my experience it is nearly always when they are too dry that Agaves do this, as SongofJoy said. So - water, but sparingly.