Iona & Peter Opie's Oxford Dictionary of Nursery Rhymes has the above text, and the text that's in the database (click). This is NOT a G-rated nursery rhyme book....
Here's what the book says about the song:

Once a playful love song, possessing its own tune. It was remembered almost solely in the nursery until 1948-9 when a dance version, popularly called "The Dilly Dilly Song," swept America and Britain. The source, titled "Diddle Diddle Or, The Kind Country Lovers," was printed sometime between 1672 and 1685 on a black-letter broadside. There were ten verses in all. Over a century later, it emerged in abbreviated form in Songs for the Nursery (1805):

Lavender blue and Rosemary green,
When I am king you shall be queen;
Call up my maids at four o'clock,
Some to the wheel and some to the rock;
Some to make hay and some to shear corn,
And you and I will keep the bed warm.

Several similar versions occur in nineteenth-century children's literature with such titles as "The Lady's Song in Leap Year" (1810) and "The Entertainment of My Dog and I" (c. 1820).

For the sake of completeness, here are the 1948/49 lyrics, from a fairly unreliable source. Can't say I ever really liked the song, but the history is interesting. -Joe Offer-

Lavender-Blue (Dilly Dilly)
Words and Music by Larry Morey and Eliot Daniel, 1948
(apparently transcribed from a 1959 Sammy Turner recording. Except for the "Whoa-oh" and some gender changes, it's almost the same as the Dinah Shore recording)
Charted at # 3 in 1959
Previously charted in 1949 by Sammy Kaye (#4), Dinah Shore (#9),
Burl Ives (#16), and Jack Smith (#17)
Sung in the film "So Dear To My Heart" by Dinah Shore

Lavender blue, dilly-dilly
Lavender green
If I were king, dilly-dilly, I'd need a queen

Whoa-oh, who told me so?, dilly-dilly
Who told me so?
I told myself, dilly-dilly
I told me so

If your dilly-dilly heart
Feels a dilly-dilly way
If you'll answer yes
In a pretty little church
On a dilly-dilly day
You'll be wed in a dilly-dilly dress of

Lavender blue, dilly-dilly
Lavender green
Then I'll be king, dilly-dilly
You'll be my queen

Then I'll be king dilly-dilly
You'll be my queen

(Lavender blue, dilly-dilly)