I would ALWAYS recommend setting them up prior to season and leaving them up. If you cant however...... try to hide them as best as you can. "brush" them in, hide them in the shadows. Believe me from experience, they will be very cautious and will even spook if they notice your ground blind! Tried to set up my blind a day before season last year..... big mistake. Thats the first thing they looked at, and looked at it every couple seconds, and would never come close to it. I will admit, it wasn't hid the best, so like I previously stated, hide it well!! This year I set it up in July and they have no issues with it. Lesson learned. Good luck!!