With the hose, wash the edging with a gentle spray, dampening the sand between the bricks without dislodging it. As the sand absorbs water, it will set, acting like grout to lock the bricks in place for years to come.
You might want to grab some patio sand at Home Depot when you see this homeowner’s brilliant weed removal trick:
How To Set Paver Stones - Sakrete Paver Set Sand. A sweep-in joint sand for pavers that hardens with moisture to prevent wash-out, lock in paver sand and inhibit weed growth. http://www.sakrete.com/products/detail.cfm/prod_alias/Paver-Set-Polymeric-Sand