Washington diary mentions the growing of hemp and seperation
of the males/females.


     I don't have ISBN numbers, but you should be able to find
Washington's Diary in many libraries.

     Here's some more information from ftp.hmc.edu in the file
pub/drugs/hemp/g.washington.grew.pot

-----------Begin g.washington.grew.pot----------------------------------
>From _Licit & Illicit Drugs_, by Consumer Reports, p. 403:

...In 1762, "Virginia awarded bounties for hempculture and
manufacture, and imposed penalties upon those who did not
produse it." 

George Washington was growing hemp at Mount Vernon three years 
later--presumably for its fiber, though it has been argued that
Washington was also concerned to increase the medicinal or
intoxicating potency of his marijuana plants.*

The asterisk footnote:
* The argument depends on a curious tradition, which may
or may not be sound, that the quality or quantity of marijuana
resin (hashish) is enhanced if the male and female plants are 
separated *before* the females are pollinated.  There can be no
doubt that Washington separated the males and the females.  Two
entries in his diary supply the evidence:

        May 12-13 1765: "Sowed Hemp at Muddy hole by Swamp."
        August 7, 1765: "--began to seperate (sic) the Male from
        the Female Hemp at Do--rather too late." 

George Andrews has argued, in _The Book of Grass: An Anthology of 
Indian Hemp_ (1967), that Washington's August 7 diary entry
"clearly indiactes that he was cultivating the plant for medicinal
purposes as well for its fiber." [7]  He might have 
separated the males from the females to get better fiber, Andrew
concedes--but his phrase "rather too late" suggests that he 
wanted to complete the separation *before the female plants were
fertilized*--and this was a practice related to drug potency
rather that to fiber culture.

-----------End   g.washington.grew.pot----------------------------------


-- 
   "A wise man will not leave the _right_ to the mercy of
chance, nor.wish it to prevail through the power of the 
majority.  There is but.little virtue in the actions of       V I V A L D I
masses of men." -- H.D. Thoreau                            

*NOTE:

It is obvious to this Editor that the Reason for George Washington's Separating male from female Hemp plant WAS INDEED for the Purpose of increased Potency...and Ingestabilty. A Hemp plant normally produces many seeds...because the pollen is air borne... The one good thing about them having outlawed it.. is that it made growing Sinsemillia (without seed )Much easier to accomplish!!! it is much more Potent and easier to smoke :-)
All the Best ..
IaHU-NaTaN
(Still puffing after over 26 years!)

__ I found this article at HempWeb