To be safe, I would treat them at the time of planting, and also physically protect them in some manner. The deer will munch anytime they're hungry. I saw a friend lose thousands of dollars of plants and saplings to deer this past spring and summer. Just FYI. April

you have a woodland? do you think that you might have an existing native seedbank that may be dormant due to the condition of the woodland?

joepyeweed: (love your handle!) I suppose there is an existing native seedbank but our woods are full of oaks, hickory, walnut & kentucky coffee trees. We'd just like to add some different fall colors, It's pretty much the same thing come fall. Don't worry, we don't plan to add any invasives like silver maple or black locust although there are quite a few locust trees already. We plan to remove all the thorny ones. I have to admit I am a devotee of the book "The Beckoning Path" by Nierenberg. I've been pouring over it for years and now that we have 40 acres of our own we're anxious to make our own beckoning path. Don't be too hard on us. ;-)