I like to do them in the fall after trimming back as I put the garden to bed for the winter. Any new spring fans are grown well and I map everything as I go along. It's also a good time to make notes for website updates on plants available. I'm working through my fall to - do list and it looks like counts & maps will be done next week. A project that can be done even if it's chilly and/or the ground is wet. With weekend rain and the temp dropping into the 50's for next week it's looking like perfect timing for that job!
