I'm looking at the photos in your diary and I'm not sure which plant you're talking about - both appear to be a lot closer than 1-month away for harvest IMO! Of course, I don't have access to the plant and a microscope to check the trichomes like you probably do. :)
You're growing in soil, so personally I would recommend flushing with plain water only for the last 7-10 days or so, and then letting her dry out for a few days, until the date you harvest. You want them to start cannibalising themselves to get rid of the remains of the nutrients in the plants. A little last minute stress with the lack of water will not have time to hurt them (some people argue it might even increase cannabinoids) and it certainly makes trimming and drying that bit quicker.
In summary: consider how long you have really left until you cut them down, keep feeding them nutrients until 7-10 days before harvest, then water only. Optional: allow her to dry out for a few days at the end and leave her in the dark for 48-72 hours before cutting her down.