Q: Can I plant my St. Patrick’s day oxalis outside? If so what are the requirements?
A: As you note, the common St. Patrick’s Day shamrock is actually an oxalis, typically Oxalis regnellii. I have some growing under an old wheelbarrow I use as a focal point in my garden and they have been happy there for years. The leaves come out in mid-March, the blooms appear in April and then everything disappears by June. This is the natural sequence of events for this plant. Put yours where it gets a few hours of morning sun and dense shade for the rest of the day. Don’t worry if you don’t see it again until next spring.