Greengage tree is producing very strange tasting fruit

Question

Around five years ago I planted greengage trees in my garden. My children and I had grown them from pips taken out of plum stones. They’ve largely grown well, but the fruit from them is not greengage-like at all; in fact they taste more like apples, and none of us like them. I’d guessed that the lack of a suitable pollinator was to blame, but before I buy other trees I wanted to clarify if that’s the real problem, or was it incorrect to grow them from pips?

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Answer 1

Unfortunately, those trees are doing what they would in nature. All of the greengage that you purchase have been grafted from a known producer and grafted to a reliable rootstock.

When you plant a seed from the fruit, you are introducing ALL of the genetic variability from both parents, one of which is probably a wild fruit.

You will always expect this from a seed planted and non grafted fruit of all kinds, unfortunately. They will rarely ever be anything like the fruit it was planted from.

Now let's get to the real issue at hand... Those are, in fact, apples. My guess is that a wild seed made it in, or perhaps the pots were mistakenly switched. There are many explanations, but none of them include changing from one genus to another.