People want to keep me I'm always very quiet half of me is a vegetable the other is a card up your sleeve. It is a five letter answer I don't know what it is

I don't know... the usual card up your sleeve is an ace... don't know what vegetable would add to that... card could be a heart, 5 letters, but what's the vegetable? Ear of corn? Got to go get some more coffee, sorry.

Found it:

Solved: The Curse Puzzle 85, 86, 87 (http://maakal.blogspot.ca/2012/12/the-curse-puzzle-85-86-87.html)

Ah well then, the question is misleading, because it says 'half' when it isn't. You can't cut 5 in half evenly anyway, so I suppose I should have thought.