How do I know if my trees will pollinate each other?
The first step is to make sure the two trees are of the same species! Then, you need to make sure that their bloom times overlap. We generally categorize our trees as having an ‘early,’ ‘middle,’ or ‘late’ bloom time. Trees in the same group will pollinate each other. Even so, there tends to be a lot of overlap between the bloom times of the different groups, so as long as you are planting two trees in adjacent groups like early and middle or middle and late, then they should pollinate without issue.
The only time you may run into an issue is if you plant an early and late bloomer together. They may still overlap but pollination may be less successful, especially in unusually cold years when bloom times tend to shorten.
Sweet Cherries and Plums are the trickiest species to get good pollination. The OMAFRA website has a helpful chart for sweet cherry pollination. We grow cherry varieties that are almost all cross-compatible as long as you get another variety of the cultivars we grow if it is not self-pollinating. And plums are even more finicky, you can see the OMAFRA chart here for them. Toka is a favourite pollinator as it's a hybrid American-Asian and pollinates both.