The appraiser is going to have to have access to all rooms or he will have to mention it in the report and the lender will require a re-inspection (another fee your going to have to pay, I mean if I was the buyer I would be asking the seller to pay since YOU prevented access, you know?) But look, the appraiser is not the police and just want to get his job done. He is just giving an assessment of value, but I have seen appraisers put comments on pot being grown in home, but I would say that is very unusual. You have a little bit to clean up that looks like a bit of a pain but your gonna have to tear it down before you move, but afterwards you could set up the lights and some fans and be good for bringing the plants back. You have ten plants, that is not too many, I would suggest:
1) move the plants the morning of the inspection to the attic, then move back after, the inspection should not take much more than an hour.
2) get some large cardboard boxes (u-haul or moving supply place) put your plant in the boxes shortly before he get there. If you are in the light cycle then put the plants outside till just before he gets there put the boxes somewhere out of the way or in your garage. You can pull all your lights and clean the area up a bit, then after he does the inspection all gets back to normal.
Worst case you tell appraiser you grow for med reasons and you keep it small for personal use, not a biggie.
