In Genesis the garden is the image of the ideal state of existence in which man and woman walked and conversed with God. The garden was lost to Adam and Eve when they fractured their connection with God through disobedience.
 And the LORD God took the man, and put him into the garden of Eden to dress it and to keep it.
 So he drove out the man; and he placed at the east of the garden of Eden Cherubims, and a flaming sword which turned every way, to keep the way of the tree of life.
|Library of Congress
Plate 47, Copy D
Blake's two characters, Milton and Blake, have both experienced Judgement in the garden having been convinced of the Error in whose grip they had been enthralled.
Perhaps you have been reminded of the experience of Jesus in the Garden of Gethsemane.
Milton, Plate 36 , (E 136)
"Thus are the Messengers dispatchd till they reach the Earth again In the East Gate of Golgonooza, & the Twenty-eighth bright Lark. met the Female Ololon descending into my Garden Thus it appears to Mortal eyes & those of the Ulro Heavens But not thus to Immortals, the Lark is a mighty, Angel. For Ololon step'd into the Polypus within the Mundane Shell They could not step into Vegetable Worlds without becoming The enemies of Humanity except in a Female Form And as One Female, Ololon and all its mighty Hosts Appear'd: a Virgin of twelve years nor time nor space was To the perception of the Virgin Ololon but as the Flash of lightning but more quick the Virgin in my Garden Before my Cottage stood for the Satanic Space is delusion For when Los joind with me he took me in his firy whirlwind My Vegetated portion was hurried from Lambeths shades He set me down in Felphams Vale & prepard a beautiful Cottage for me that in three years I might write all these Visions To display Natures cruel holiness: the deceits of Natural Religion[.] Walking in my Cottage Garden, sudden I beheld The Virgin Ololon & address'd her as a Daughter of Beulah[:] Virgin of Providence fear not to enter into my Cottage What is thy message to thy friend: What am I now to do Is it again to plunge into deeper affliction? behold me Ready to obey, but pity thou my Shadow of Delight Enter my Cottage, comfort her, for she is sick with fatigue" Plate 37  The Virgin answerd. Knowest thou of Milton who descended Driven from Eternity; him I seek! terrified at my Act In Great Eternity which thou knowest! I come him to seek" Milton, Plate 39 , (E 140) "Suddenly around Milton on my Path, the Starry Seven Burnd terrible! my Path became a solid fire, as bright As the clear Sun & Milton silent came down on my Path. And there went forth from the Starry limbs of the Seven: Forms Human; with Trumpets innumerable, sounding articulate As the Seven spake; and they stood in a mighty Column of Fire Surrounding Felphams Vale, reaching to the Mundane Shell, Saying Awake Albion awake! reclaim thy Reasoning Spectre. Subdue Him to the Divine Mercy, Cast him down into the Lake Of Los, that ever burneth with fire, ever & ever Amen! Let the Four Zoa's awake from Slumbers of Six Thousand Years Then loud the Furnaces of Los were heard! & seen as Seven heavens Stretching from south to north over the mountains of Albion" Milton, Plate 42 , (E 143) "And I beheld the Twenty-four Cities of Albion Arise upon their Thrones to Judge the Nations of the Earth And the Immortal Four in whom the Twenty-four appear Four-fold Arose around Albions body: Jesus wept & walked forth >From Felphams Vale clothed in Clouds of blood, to enter into Albions Bosom, the bosom of death & the Four surrounded him In the Column of Fire in Felphams Vale; then to their mouths the Four Applied their Four Trumpets & them sounded to the Four winds Terror struck in the Vale I stood at that immortal sound My bones trembled. I fell outstretchd upon the path A moment, & my Soul returnd into its mortal state To Resurrection & Judgment in the Vegetable Body And my sweet Shadow of Delight stood trembling by my side Immediately the Lark mounted with a loud trill from Felphams Vale And the Wild Thyme from Wimbletons green & impurpled Hills And Los & Enitharmon rose over the Hills of Surrey"