Is this a complete sentence?

A bushy, overgrown hedge along the fence.

No that is not a complete sentence becuz it needs like more details.

Nope. That is considered a fragment.

The subject is present: A bushy, overgrown hedge [located] along the fence.

This can't be complete, however, because there is no verb and such to explain much else.

A complete sentence could be "A busy, overgrown hedge along the fence caught my attention."

*caught is a verb.