Green’s Dictionary of Slang

Common Garden n.

Covent Garden, London; also attrib.

1821–6		‘Bill Truck’ Man o’ War’s Man (1843) 41: I’ll tip you the fag-end of a Common-Garden ditty.
1827		J. Wight More Mornings in Bow St. 114: Mr. Gough sen., ‘a seller of cabbages by commission in Common Garden’ [...] Mr. Gough, jun. was busly engaged in Covent Garden market [etc].
1838		Dickens Oliver Twist (1966) 192: You know there are fifty boys snoozing about Common Garden every night.
1845		R.S. Surtees Hillingdon Hall I 146: I declare its a pinery! real pines a growin’ quite nattural, instead of perched on plates, as one sees them in Common Garden.
1871		Sportsman (London) ‘Notes on News’ 10 June 4/1: Mr Vaughan: What is your father? Where does work? Prisoner: Common-garden-market.—Gaoler; He is a porter In the market, your worship.
1866		J. Greenwood Little Ragamuffin 104: ‘Is it near Covent Garden?’ I asked. ‘What, Common Garden Theayter?’ answered Mouldy.

In compounds