Will a Bartlett Pear, semi dwarf and an Ayres Pear, semi dwarf pollinate one another? I am new to fruit trees and don't know anything (yet!). These trees were in 5 gallon pots at half off this morning (so they were marked down to $18.) There were very few left and so I thought I'd better get them before they're gone. If they don't pollinate each other, what should I buy as a pollinator? Thanks in advance for any advice you can lend!