This raises a simpler question, is it better to collect at night [cooler wetter etc]?
I agree with Jason on the first part of his statement...I have collected at night because that is the time I was given permission to do it...was a logistical nightmare.
As for the second part...maybe not so much. While a tree may survive being collected in a hotter and a more arid environment. The recovery time is very, very different. Most, if not all, propagation instruction states that these procedures should be done early morning / late evening to reduce stress on the material. Yes propagation and collecting are different but do loosely fall into the same genre.
Now saying all this.....keep in mind that collecting Bristlecone, Ponderosa, and RMJ that thrive in a warm and arid environment is a lot different than collecting Hornbeam, Pitch pine, Maple and Yew that are all generally low altitude species.
I agree 100%, and I should have said the species and climate play hugely into when, where and how you should collect. Maples I collect in early spring (as the snow allows us to reach them) and in late fall just before snow fall.
Thanks for pointing that out for me Tom!!
Haven't been out this year yet. The snow isn't gone in the cascades and I just started a new job (YEAH!!!) so I won't head out for a long trip till end of summer. Randy at Oregon Bonsai just got back from his first trip to RMJ country this past week. Nice haul....