One of the biggest mistakes I see home gardeners make in their fruit tree selection is not knowing if the variety they are growing needs a pollenizer. (The second biggest mistake is not knowing about chill hours. Read about that here.) If it needs a pollenizer and you don’t have one planted near by, guess what? You get no fruit. Your tree will bloom, bees will visit and thank you for the pollen and then the blossoms will fall off leaving no fruit. So what’s a pollenizer? In fruit tree terms it is simply another variety of the same type of fruit tree that will pollinate your tree. Which is not to be confused with a pollinator which is something like a bee that takes pollen from tree to tree, but you need those too.
For example if you want to grow cherries and have your heart set on growing Royal Rainer cherries, you can’t just plant a Royal Rainer cherry tree. You also have to get it a pollenizer. For a Royal Rainer cherry you would also need to plant a Bing, Lapins or Black Tartarian tree. Can you just plant two Royal Rainer cherries? No, the pollenizer always needs to be a different variety of that fruit tree. What if you want to plant another type of cherry, like a Minnie Royal? Well, you can’t do that either. The pollenizer has to also bloom at the same time as the tree you want pollinated and that’s a pretty specific window. How will I know if it needs a pollenizer? Well a reputable nursery should be able to give you that information. But what if they are having a great deal on trees at Costco? Then you will need to Google the information (and while you are at it, make sure to check the chill hours.) The pollenizer also needs to be planted within 100 feet of the tree you want pollinated.
But what if you have a small space and can only fit one tree? Well, you have several options there. If you only want to plant one tree, you need to look for one that is self-fruitful. (This is the option I recommend. Make the right choice and you are done.) In the case of a cherry tree, that would be a Stella variety (but it does also need 500-800 chill hours). Another option would be to get your nearby neighbor to plant a pollenizer (Or perhaps one already exists). Your third option takes a bit of skill, but can be learned, is to graft some branches of the pollenizer onto your tree. Your fourth option, and it’s not one I really recommend because it’s labor intensive, is to purchase pollen when your trees are blooming and hand pollinate.
I can normally find the information I need with a quick Google search, but I keep the Dave Wilson Nursery website bookmarked as it has all the information I need and it is where we get our trees from to sell at the nursery.