Why SMS if you can trip a notification on the phone in the calendar app?
I don't think you can. Perhaps there are third party calendar apps that can? However, the workaround is to set the email notification and send to the email address gateway for your phone number (ie, on Verizon,
[email protected]). That will give you an SMS reminder.
You can also open the desktop version of google calendar in chrome on the phone and set the SMS notification that way.
Finally, you can set Google Calendar to notify by SMS for all events entered by default. You do this in the settings for the calendar on desktop Google Calendar, but it will stick and be used for all future events.