* Bláth beag Éireannach: This is a fairly literal translation. "Bláth" (blaw) means flower, "beag" (bayg) means little/small, and "Éireannach" (Eer-in-ach) means Irish. This is a good general option.
* You could replace "bláth" with a more specific flower name if you know it. For example, if it's a little shamrock, you might say Seamróg beag.
The best choice will depend on context. If you are writing poetry or something more evocative, you may find a more poetic translation. If you need a very straightforward translation, "Bláth beag Éireannach" is a good starting point.