We don't tend on the British mainland to make much of the patron saint's days of England, Wales and Scotland.
Some groups have small celebrations, some towns might put on a parade, dancing and other activities. Flags with the image of St George's cross are flown on some buildings, especially pubs, and a few people wear a red rose on their lapel.
However for the majority of English people it is no big deal, most I doubt could even tell you the date of St. George's Day. It is probably a date better known by some as the anniversary of Shakespeare's birth.