What I do, when I first notice this (say for heads mistakenly left in the ground), is try to catch them when they are still small - first popping up - I dig all of them up, gently pull them apart, and replant each one separate, 5 or 6" apart (depending on variety). If caught early, I often still get nice heads out of these.

A friend rented a house for her child to use for four years of college.

The owner put it up for sale & the mother bought it & has lived in it for over a year.

I was at the house & noticed a clump of garlic growing by the dog pen.

The new owner said they did not know it was garlic, so it has been growing with out any care for at least 5-7 years.

Question I want to ask is this Elephant Garlic, if not then what kind?

When is the best time to transplant the bulbs into rows?

A way to tell if it is elephant garlic is to dig the clump when the leaves are about half yellowed and dying, usually mid June to mid July (for me zone 7). As you are exposing the bulbs, if there are small yellow to brown "buttons" lightly attached around the main head of garlic, then it is possible it is elephant garlic. Of course, leeks may do this same sort of thing, and there may be some large allium varieties that may do some of the same thing.

Yes Elephant garlic has corms on mature bulbs.

Not sure if it will die down or when, but I will dig it when it has yellow leaves.