I'm trying to chalk up a compendium of stuff that was crossbred. See if there are rules (which there are) to what you need to breed to breed something. For instance see if we can find a connection between tiers. Any information?
Wheat (t1) + Rose(t2) made Black thorn (t2)
Rose(t2) + dandelion (t2) made black thorn (t2)
Reed(t2) + Reed(t2) + Stick Reed (t4)