I would be concerned; my quince at two years was putting out 4-foot new growth.

Assuming other nearby plantings have grown more in the past two years, your quince roots have simply not taken hold and grown. So I would suspect the soil or the roots.

Was this a bare-root tree, or was it in a container or burlap?

Since it was two years ago, I honestly can't remember how it came, larry_gene. It was from Forest Farm nursery. To me, the tree seemed way too tall for its small width.

I suspect the soil may be partly to blame. The tree has nice green leaves, though. Is there anything I can do to help it out? Would putting some compost and/or mulch around the tree help perhaps?

I'm having similar problems with other trees as well. They're over a tenth of a mile away, but the soil may still be the problem. For instance, I planted a 4-foot olive tree in April '11, and it doesn't seem to have grown in height one bit. Same with a 4-foot Fuyu persimmon tree also planted that month.

For the growth to be stunted in all these various plantings, there must be a soil or planting method problem.

Mulch and compost may help--but it could take a couple more years to see results. Actual fertilizer is not recommended for quince, but at this point it would be interesting to try fertilizer next spring and see if it kick-starts some growth.

Do you have other successful fruit tree plantings in the area?

Thanks, larry_gene. We have many fruit trees that are over 10 years old. Our pear trees are about 30 feet tall and were planted some time in the '80s. The pears aren't great (some rot before they ripen), but they're edible for the most part. We've got some big apple trees too with decent fruit. Also some big plum trees, but the worms always get them. Our fig tree is 15 years old, and it's been having wonderful fruit for at least 10 years. OTOH, our pomegranate tree is about 7 feet tall and produces flowers, but no fruit. But our dwarf cherry was only planted in 2008, and it's been producing lots of cherries since 2011.

So, anyway, I don't know what to say. I'll try mulching and compost and see what happens. :) Are there any other "natural" ways to see results, without using commercial fertilizers?