OK, what kind of trees are these
 

I just noticed we have two trees loaded with fruit that appear to be citrus. My understanding, as a Kansan, is that citrus ripens in the winter. These are lemon sized or so and I cannot tell if they are yellowish turning dark green or the other way around, but they are good sized. Plus each tree has one or two the size of grapefruit. What could they be?

Grapefruits?

I'm thinking a grapefruit tree. You'll find fruit of various sizes and colors on trees. Fruit stays on the tree until it fully ripens and sweetens up, generally months after it appears ripe.

So what time of the year do grapefruit ripen?

Different varieties of citrus ripen at different times. For example, Navel oranges ripen in winter, Valencia oranges ripen in late spring/summer. Meyer lemons bear fruit pretty much any time, with flowers, unripe and ripe fruit on the tree at the same time. Ponderosa lemons can have fruit the size of grapefruits, and pomelos have fruit close to soccer ball size. So keep an eye on the tree and see what develops.

I have also been told that there are hybrid trees here with several different types of fruit on them all at the same time!

We have a navel orange tree grafted to a citron tree. Both ripen in the winter. When ripe, the citrons are yellow with a nubby skin. The citrons are virtually inedible but the oranges are delicious (and plentiful - last year we got 15 dozen off a small tree.)

The citron is the tree's rootstock. All citrus trees are grafted to a hardy, and usually inedible, rootstock. You can see the union of the graft, usually a foot or less from the base of the tree. Any shoots or branches that come from the root stock should be removed. They take energy from the good part of the tree and will eventually take over.

Trees that have several types of desirable citrus on one tree (such as lemon + orange + grapefruit) have multiple varieties grafted to a single rootstock.

The comment about your naval orange tree grafted on citron is because of our cooler winters, the citron root is freeze hardy. The other comment about several types of fruit on one tree is actually different types of citrus trees grafted on one root stock, again because of our freezes here. They are called fruit cocktail trees. Eventually as they age all the fruit will taste the same. Grapefruit usually starts to ripen in late fall and can be picked all through the winter. If it is big and green it is probably a grapefruit. Hope this helps.

As noted .... different citrus ripen at different times. I had a white grapefruit that was not ripe until late spring. IMO .... most citrus benefit greatly from a bit of cool weather (as in 40's to upper 30's) the trees naturally try to save the babies and it sweetens them up!!

Also, citrus from sour root stock makes the best marmalade.

At one time I had 13 different citrus trees in my yard (Orlando area) .... the freezes of 83 & 85 killed all but 3 of them. Those freezes were also largely responsible for driving the citrus industry in the state south of I-4. At one time the area around TV was the heart and soul of the Fla citrus industry. Especially Lake & Citrus Co's.

By that time (mid to late 80's) most groves were owned / operated by 2nd even 3rd generation owners. They did not have the "feel" for the land and industry that daddy / granddaddy did. Sooooooo, when faced with big $$$$$$ to replant and then wait 7+ years for a decent harvest or take big $$$$$$ from developers to sell the land .... if was easy math for most of them.

OldDave:

Have you learned anything yet in this thread? I've been trying to follow it, and have come to the conclusion that, no matter what you actually have in your yard, it'll be somehow or the other positively or negatively affected by local conditions!

Isn't it fun?

SWR
:beer3:

Yeah, considering my original question was what is on trees this time of year rather than heading into winter, I don't feel I have much of any idea. But hell, I'm not supposed to eat citrus anyway, so it doesn't matter much.