Sorry for not responding I've been busy this week.Do the Trees need to be pure bred to crossbreed?
No they don't need to be pure bred but I believe just like bees they also have a chance of using both the species when mutating so you may not get the mutation you want.
For anyone who has successfully bred a Willow tree, what biome were you located in? I never got one in Plains or Woodlands despite tons of bees & trees interacting and was only finally able to get one when I setup a pair of Marshy bees surrounded by the appropriate trees in a Swamp.
And also, I love the grafter. That one simple device has made tree breeding about 10,000 times less tedious and annoying. In the two days since our server upgraded to Forestry 2 as part of Mindcrack 8 I have gotten more new tree species than in the previous couple of weeks under the old version of Forestry. Yeah, I may have burned through most of a stack of bronze, but the only trees I have left to "discover" are the Yellow Meranti and the three whose breeding is bugged in version 2.0.0.2 (Wenge, Baobob, & Sipiri).
Glad you confirmed this for me as I also got a willow by breeding in a swamp. I'm not sure if its impossible to get in other biomes, but I got one very fast before 2.0 and the grafter in a swamp and never have gotten one in the plains biome my other trees are in.