I've seen this quoteseveral times on Facebook. I did a little Googling but was unable to find any proof or citations regarding its credibility. From what I know about Washington, it doesn't sound like something he would say.
"It is common on the Internet to falsely attribute to someone in the past a quotation addressing something that's an issue today but not an issue at that time." -- Booker T. Washington
Over in /r/BadHistory, More Founding Fathers Fails asserts that Washington never expressed those words, giving three sources of archives:
Was George Washington the source of this quote equating government gun control with evil intentions? has some discussion. It states that Eric Gustafson located a source, and it wasn't George Washington:
The author of the quote appears to be someone named Joe Spenner who authored a pamphlet in which there is an introduction by Spenner (note the absence of quote marks - he isn't quoting) containing the phrase in question, below this a horizontal dividing line, below the line are a series of quotations (in quote marks) attributed to George Washington. It seems clear that the quotation in question is part of Spenner's introductory remarks and Spenner is the original author.
There is more information on that page, including 'The phrase "evil plans" does not appear in George Washington's written works 1745-1799'
As for the quotations in the pamphlet, the author says nothing more than "Address to the Second Session / First United States Congress". I've looked at Washington's State of the Union messages, http://gwpapers.virginia.edu/documents/washingtons-first-annual-message-to-congress-and-congressional-responses/ et seq. 1790 has a bit on arming, but briefly:
A free people ought not only to be armed but disciplined; to which end a Uniform and well digested plan is requisite: And their safety and interest require that they should promote such manufactories, as tend to render them independent on others, for essential, particularly for military supplies.
The proper establishment of the Troops which may be deemed indispensible, will be entitled to mature consideration. In the arrangements which may be made respecting it, it will be of importance to conciliate the comfortable support of the Officers and Soldiers with a due regard to œconomy.
I see nothing else through the third, in 1791. There may have been other addresses in the archives above, but I haven't the time to check.
It doesn't sound like him at all. George Washington was always in favor of a well trained and disciplined militia. Most of his writings about the topic emphasize that he wanted a well armed, well trained, well disciplined militia. His desire for this probably had less to do with gun control and more to do with being tired of building and training an army.
Mount Vernon has a list of Spurious Quotations. The second quotation in its actual context provides a good idea of Washington's position and also his style.
On another note it does sound similar to something Samuel Adams would say. Again the style isn't right but the sentiment is in keeping with his general views. Samuel Adams was much too eloquent to say anything in such a crude manner.