Simply ,Yes weed grows outdoors in Ireland.Choose an outdoor seed variety and feminine seed eg Holland Hope.
You don't want many plants if you are caught just 3 or less for personal use. My plants grow typically 6' or more each year.
You need to stake them from high winds and pick the buds on first frost.The strength is the same as indoor grown without the cost.
A tip, when you are cutting the buds by hand .You will notice the resin on your hands scrape this off .A minute amount is all that is required
to give you a super blast.
I strongly suggest keep your activities secret.
Follow online directions using search .