I know man, it is really hard to get any clear guidlines. Here is the attorney generals guidlines which does mention fire arms and collectives ro dipsensaries.
http://www.ag.ca.gov/cms_attachments/press/pdfs/n1601_medicalmarijuanaguidelines.pdf I think the answer is do not have guns in your house if you are growing, shich is fucked because I can't imagine not having protection in my home. I would say from what I have been reading that it is up to the descretion of the officer and I would not have a gun in or near your garden.
This is the part that mentions weapons, still not very clear.
2.
Indicia of Unlawful Operation: When investigating collectives or
cooperatives, law enforcement officers should be alert for signs of mass production
or illegal sales, including (a) excessive amounts of marijuana, (b) excessive
amounts of cash, (c) failure to follow local and state laws applicable to similar
businesses, such as maintenance of any required licenses and payment of any
required taxes, including sales taxes, (d) weapons, (e) illicit drugs, (f) purchases
from, or sales or distribution to, non-members, or (g) distribution outside of
California