One of the EU pillars is free movement of goods, meaning that you generally can't prevent someone from a different country from selling goods in your country.

This means that the decree is either incompatible with EU law, or it is pointless as you'd just be killing your own domestic market while exposing yourself to other EU countries anyway

GP's mistake was assuming that this isn't pure virtue signalling, the decree is compatible with EU law because it applies only to italian producers

So if netherlands legalizes marijuana then Greece can't outlaw it because EU law?

Seems pretty absurd!

States have the right to set standards on the market regardless of Brussels.

It's already illegal in Greece so your argument is nonsensical

If you notice part of my comment was "generally"

Drugs tend to be an exception to most things