A wood pergola can be a great way to reduce the amount of sunlight heating up your wood deck surface. It can offer shelter from the smoldering sun on extremely hot days without fully enclosing your deck. A pergola can also stand alone in a garden, over landscape features, over a hot tub and more. Like any exterior wood surface, a pergola should be protected with a wood stain to increase its appearance and lifespan. Knowing how to stain a wood pergola is key.