It is safe to still eat. The green growth is edible. What I like to do is take the small cloves and early sprouters and plant them in a pot for a window or outside on the deck. I use the greens just like spring onions. They taste great. Have that garlic kick like a scape. Great in/on scrambled eggs or stir fry. If they are big nice bulbs, and you don't want to eat them, there is no reason why you can't plant them. It's just about that time anyways.

I understand some Chinese cooks keep dishes of sprouting garlic cloves growing on watered stones and use the sprouts in the cuisine. It is one way to more or less have scapes all year around. The green is supposed to be a bit milder than the cured bulbs are and even if showing the start of sprouting they will certainly grow if planted. The green on garlic is not dangerous like the green on potatoes is.