Why does feta cheese not grow in Northern Ireland?

Feta cheese doesn't grow in Northern Ireland (or anywhere else for that matter) because it's not a plant, it's a cheese.

Feta is made from sheep's milk (sometimes goat's milk is added), and the climate in Northern Ireland is suitable for sheep farming. However, the specific conditions required to produce feta cheese, including the use of traditional techniques and the presence of certain bacteria, are not readily available in Northern Ireland.

So, while the ingredients for feta cheese might be available, the actual cheese itself is not "grown" but rather produced through a specific cheesemaking process.