Hello...Long-time lurker, new-ish citrus hobbiest. I know this is a long post, so thank you very much for taking the time to read!

We bought our house north of Houston 1.5 years ago with 2 citrus trees in the back yard. They are both 15-20 feet tall and appear to be the same variety. Neither have flowered or fruited, but by there leaves I believe that they are grapefruits. They are shaded by pine trees, but get a lot of dappled shade all day with a few hours full sun (I have other citrus fruiting in the same circumstance: Satsuma, Meyer Lemon, Limequat). The trees appear healthy to me. On to the questions:

1.) Do you agree that these are some variety of grapefruit?
2.) Do they look like grafted trees or seedlings?
3.) Are the trees tall and thin due to part shade, being seedlings, or what?
4.) Why haven't they fruited or flowered yet?

They are in a difficult place to take photos, but here is the best I could do:

Leaves:


Tree bottom:


Tree top:


Graft??


Thanks!

Yes they do appear to be seedling grapefruit. Grapefruit by nature take longer than most citrus to fruit from seed. Grapefruit on average take 10 - 15 years from seed to produce fruit.

I agree with Laaz, they looks like seedlings. I can't see any marks of grafting.

PS. Leaves on the first photo are covered with small yellow points. I think they are damaged by a pest, probably red mite. Check it out.

I agree with both--it does look like GFT and those tiny yellow specks look like red spider mite bites. Look for tiny red brown smears when you rub the bottom of the leaf. Spray with hort oil--top and bottom of leaves as well as the trunk.

Seeing the cork, couldn't it be a macrophila? Rootstock that overgrown the graft.
Someone with a old grapefruit could tell us how is the cork?

Thanks for all the replies.

The leaves are actually covered with yellow pine pollen, but I do need to get out there and blast the tree with a hose.

If it is overgrown rootstock, wouldn't it have flowered by now? Is there a common rootstock variety that takes this long to fruit?

Normally in your area if it were grafted it would be on Swingle or Trifoliata. I don't see a graft line and if they were grafted they would have fruited by now.

Macrophila is not cold hardy and would not be used in your area. I have yet to see any citrus here in the southeast grafted to Macrophila.

Normally there is a line where the graft was made. Most of the time there is severe benching at the graft union with the fast growing understocks are used. There is no visiable grat line on the tree.

Thanks for giving this a look and for the replies. I guess I will wait it out and see what happens...hopefully it will fruit in the next couple years.