"He took an orange from the cupboard . . ."
Sherlock Holmes has a cupboard with oranges in it in his sitting room.
"Near the foot of the bed stood a dish of oranges, and a carafe of water."
The "leading man" in the neighborhood of Surrey near Reigate kept oranges in his bedroom. Sherlock Holmes knocked them over at a key moment in that case.
Yet despite them being mentioned so prominently in the title of one of the classic Sherlock Holmes tales, oranges are just not something that we associate with Sherlock Holmes. Apparently he enjoyed them enough to keep an orange or two on hand in a nearby cupboard, though.
Oranges where imported from warmer climes like Spain, unless one were wealthy and fancy enough to have an "orangery" built on one's estate. They were slightly seasonal, easiest to find around Easter, but coming in from October to August, but cheaper after Christmas and going up in price around May. (All this according to Mayhew works, which pre-date Holmes and Watson's era by a couple decades.) Mrs. Hudson probably picked up 221's citrus from "a coster's orange barrow" like Watson used as a metaphor in "Red-Headed League."
These days we associate orange juice with breakfast, and I have to wonder if oranges were something of a morning treat from the two contexts we have in the Canon, old Cunningham keeping them near his bed and Holmes keeping them so handy, something to start the day before proper breakfast, both juicy and vitamin C friendly.
One might think of Sherlock Holmes's relationship with oranges as a negative one, as he tears one up and knocks over that dish of them, but that little detail of the orange in the cupboard -- that little detail so indicative on an ongoing part of everyday life in Baker Street: Oranges, when in season.
I've probably squeezed as much juice out of this topic as I can -- now that I've gotten that bit said -- so the next time you're enjoying an orange, maybe focus on its potential as a part of the tastes of Baker Street instead of just trying to count out five seeds to send to your friends? Maybe.