Answer: Most pear varieties are self-unfruitful. However, nearly all pears are suitable pollinizers for other varieties that bloom at the same time. Your Gala and Jonathan apples are compatible so you should have a heavy fruit crop from both. Most European plums (e.g., Bluefre, Blue Ribbon, Earliblue) either benefit from or require cross-pollination from another European variety. However, European or prune-type plums, such as Stanley and Damson, are self-fruitful.
Best wishes with your fruit trees.
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