I was recently choosing some pear trees to plant on my property in Durango, CO and was making sure to get the right varieties for cross-pollination. Pears are very particular so you must make sure that the pears you select will ensure pollination. The Fruit Tree Pollination Fact Sheet is a great reference. We were at Durango Nursery identifying their selection. Since pears are more difficult to grow, the choices were limited to a few varieties. We ended up choosing a Bosc and Bartlett variety since the Bartlett and Djanjou wouldn’t work very well together. The Bosc variety is a good choice. The varieties of pears need to be growing within approximately 500 feet of each other, the closer the better.
It is important to make sure that you know if your fruiting tree needs a pollinator, so before you buy, find out. If you are going to plant a fruit tree, you most likely want it to bear fruit.
A great tool also to use is Tree Browser, which helps you to pick out appropriate trees of all sorts for the region that you live.