Well, April is a bit late on planting garlic, at least for a really good harvest. But generally speaking, I'd expect you could leave it in it's place and get something. Plus, as long as it survives, you could replant, come fall, and have a much better harvest next June or July.

I'd leave it and hope for the best.

George

George had some good comments. I'm heading to work but will try to leave some comments later.

I agree with George that it is likely to survive. Well, unless it gets one of the rot diseases. It is hard to tell just from hearing about it if it is merely suffering from being too wet or if it may have developed a rot disease. I think you have nothing to lose by leaving it in the ground and letting it grow. It might even die down to the ground and then regrow later in the summer if the weather ever stops dropping constant rainfall.

Elephant garlic is not actually a garlic either. It is a variant of the leek family, so I am not sure how much it grows like garlic or how much it grows more like leeks. I don't grow it often because it has a mild flavor and I like the stronger flavor of true garlic. We'll have to wait to see what our Garlic and Tomato King has to say about it later.