A word of advice from one who used do this kind of shoot regularly - plan to shoot towards the end of spring, just before the plants begin to come to life again. Things are generally dryer and warmer if timed correctly, and with no leaves or undergrowth you can find sites are almost clear, even if they were almost covered with greenery a few months earlier. Only drawback can be boggy wet ground, which you don't get in autumns, as the water has yet to accumulate. Summer might be nicer, but having to turn up with shears and loppers just to get access gets a little tiresome, and seldom works as it takes so long.