Q.plum trees
I live on the south coast, with heavy prevailing SW winds. My Edwards plum is covered in blossom, and many small green plums, but come ‘harvest’ only 3 remain on a 20-foot tree. Is it the wind? Fertiliser? We have few frosts.
Thanx
Bob

Certified GKH Gardening Expert
It may be that animals ate the other plums. The wind may have blown some down as well, but then you'd see the fallen plums on the ground under the tree. Check whether you see any signs of nibbled-on plums in the area.
Here are some options for protecting your fruit from birds, squirrels and others next year:
https://www.gardeningknowhow.com/edible/fruits/fegen/squirrel-proof-fruit-trees.htm
https://www.gardeningknowhow.com/edible/fruits/fegen/protect-fruit-tree-birds.htm
https://www.gardeningknowhow.com/plant-problems/pests/deer/deer-eating-fruit-trees.htm