Apple tree from seed ??

[kentish girl]

I spotted some sprouting seeds from Jazz apples & put them in compost to see of they would grow. They are now 2" high & looking good.

Would I be right in assuming that they may not turn into true fruiting trees

[FB.]

The characteristics of seedlings is very variable - just as children can be very different from their parents and very different from their brothers and sisters.

You probably won't get anything resembling Jazz apples from your seeds - many commercial orchards use crab apples as the pollinator, so your seedlings may well be some kind of crab-eater hybrid.

In my experience, seedlings from shop-bought apples are very prone to disease and end up as reservoirs of disease that spread to nearby fruit trees.
Quite often, they aren't happy with the local soil or climate - many will die.

I no longer bother experimenting with seeds from shop-bought fruit (I have sometimes tried to grow them for use as rootstocks), although I may occasionally continue with using a few Golden Delicious seedlings, which have a good reputation for use as rootstocks.

I am having good results with disease resistance and hardiness in some seedlings of my own breeding, using varieties that grow well for me.
My super-disease-resistant crosses are from; Discovery x D'Arcy Spice and Discovery x Tydeman's Late Orange.

As for what the fruit will be like, and how long I might have to wait, and how heavy/regular the crops might be.....
......I expect that I'll probably end up using the seedlings as rootstocks, since, when I last trasnplanted them, they all had very large and strong looking root systems that looked well up for the job of supporting a very big tree once they're mature.