How did Napoleon try to hurt England's economic growth during the Napoleonic wars

He introduced the so-called Continental Blockade, which would disable Britain to trade with any of European countries that Napoleon controlled or had alliance with.

Explanation:

In Berlin, Napoleon drew up a plan to crush his main adversary, Britain, and set out his plan in a document known as the "Berlin Decree," which imposed a continental blockade of Britain on Europe because he realized after Trafalgar that he could not invade Britain. So, the continental blockade should commercially completely isolate Britain and thus economically exhaust it.