The orchard is the massive, hulking presence at the play's center of gravity; everything else revolves around and is drawn towards it. It is gargantuan; Lopakhin implies in Act One that the Lopakhin's estate spreads over 2,500 acres, and the cherry orchard is supposed to cover most of this. There were never any cherry orchards of nearly this size in Russia. And the fact that an orchard of this gargantuan size, which, by the estimate of Donald Rayfield, would produce more than four million pounds of cherries each crop, cannot economically sustain Ranevksy is an absurdity.
But it is absurd for a reason. After all, the orchard used to produce a crop every year, which was made into cherry jam. But, as Firs informs us, now the recipe has been lost. It is thus a relic of the past, an artifact, of no present use to anyone except as a memorial to or symbol of the time in which it was useful. And its unrealistic size further indicates that it is purely a symbol of that past. In a very real sense, the orchard does not exist in the present. It is something that is perceived by the various characters and reacted to in ways that indicate how these characters feel about what the orchard represents: which is some aspect of memory.
What "memory" means for each character and what it represents varies. Each character sees-sometimes literally—a different aspect of the past, either personal or historical, in the orchard. Ranevksy, for example, perceives her dead mother walking through the orchard in Act One; for her, the orchard is a personal relic of her idyllic childhood. Trofimov, on the other hand, near the end of Act Two sees in the orchard the faces of the serfs who lived and died in slavery on Ranevsky's estate; for him, the orchard represents the memory of their suffering . For Lopakhin, the orchard is intimately tied to his personal memories of a brutal childhood, as well as presenting an obstacle to the prosperity of both himself and Ranevsky.
Though each character has their own perspective, there is a rough division between the old and the young, with the age cut-off being between Lopakhin and Ranevksy; the young tend to view the orchard in a negative light and the old view it more positively. This further reinforces the orchard's symbolic identification with the past. The one exception to this may be Varya. But this exception proves the rule, for though Varya often talks about the estate, she never mentions the orchard itself at all. For her, it is irrelevant, and the estate is what is important, for she is its manager, and its ownership is directly connected to her livelihood.
No one knows what it is when we first hear it in Act Two, and when we last hear it, the only character onstage is in no position to comment. It is the sound of breaking string, an auditory symbol of forgetting. It first is heard in the play after Gayev gives a soliloquoy on the eternity of nature; Firs tells us it was heard before, around the time the serfs were freed (a seminal event in Russian history). It is last heard just as Firs, the old manservant who functions as the play's human connection to the past, passes away, and is juxtaposed against the sound of an axe striking a cherry tree. With its simple image of breaking line, the sound serves to unify the play's social allegory with its examination of memory, providing a more graphic counterpart to the Cherry Orchard's hovering, off-stage presence.