Answer:
Literally, a 'bed of roses' describes a formal or semi-formal flower bed dedicated to growing roses, in a private or public garden.
Figuratively, as an idiom, the phrase means - of a person or animal - (living in, or being in) a state of luxury; an environment or situation of ease, comfort and pleasure.
The idiom is said to originate with the English poet Christopher Marlowe's poem, 'The Passionate Shepherd to his Love', published postumously in 1599 (the poet died in 1593), but thought to have been written in his early years between the ages of sixteen and twenty three:
'And I will make thee beds of roses
And a thousand fragrant posies,
A cap of flowers and a kirtle
Embroidered all with leaves of myrtle;'
Certainly the figurative use of the phrase 'bed of roses' traces back to 1590s English, though whether the poem came first or whether the phrase, already in use, inspired the poet cannot be known. In his reference to 'beds of roses' the poet isn't suggesting the shepherd's lady will lie, possibly with the shepherd, upon great, fragrant piles of rose-petals; Marlowe has the shepherd, instead, simply promising to dig flowerbeds and plant a lot of roses for the delight of his darling. The noun 'bed', describing a garden bed, as well as a shallow bed dug in the earth for sleeping (as many shepherds and other rural workers would have slept), goes back to Old English and Old Saxon, and roses - as well as other cultivated plants - were grown in beds long before Marlowe's shepherd offered to do some gardening for his love.
Today, with literal beds of roses less commonly found in urban gardens, the imagery evoked by the phrase 'bed of roses' does not usually include vistas of rose-gardens; more popularly the images are of rose flowers, or petals, strewn or heaped lavishly about the place, frequently with people or pampered pets lying luxuriously in or upon them.
Recent usage of the phrase include the 1996 movie, 'Bed of Roses', a romantic drama about a girl and a florist, and, in Australia, the television drama, 'Bed of Roses', a light one-hour drama series due to conclude in 2011, about a woman who loses her life of privilege and comfort and finds happiness and histrionics in a little country town. As well, musician Jon Bon Jovi composed and released a song titled 'Bed of Roses', ©1992.