A long time. Ours started falling in Sept. Way early for us. Still lots of leaves left on the trees. They are good to add to a compost pile. Hubby just mows over them. Leaving them in place too long kills the grass. They give us the best shade. Maples don't grow very well here.

Around here the Water oaks and Laurel oaks are the worst, they'll still be dropping leaves into January.

The oddity is Live oak, which sheds it's leaves in early spring while flowering.

There's an old story about the farmer who borrowed money from his neighbor one autumn, promising to pay it back when the last leaf fell from the old oak in the neighbor's yard. The loan never was repaid, lol.

Ditto the suggestion to mow them up. I do not know where my rake is. I have a leaf blower to get em away from my house and garage and a mower to turn them into next year's fertilizer.

Our Shumard holds the majority of its brown leaves almost until the live oaks start dropping theirs in early spring. Other oaks are also known for marcescent leaves.

Here is a link that might be useful: When oak leaves fail to fall (Morton Arboretum pdf)

Water oaks tend to hold on to thier leaves for a long time but thank god that all of mine fell off in the last week. Now i just have to get my lazy butt out there and get the leaves up!

My pin and shumard won't shed all leaves until spring. Pins hold onto more than shumard in my yard. All other oaks I have (willow, northern red and nuttall) drop almost all by new years.

I don't mind if my grass dies, I have mostly weeds and some grass, no manicured lawn anyways. I don't care if I have them laying on the grass til spring, then mow along with the grass. Maybe someone with warmer winters, where your yard/lawn is actually noticable in winter. here even if there is no snow on the grass, we're all like "damn, it's cold get in the house ASAP". I personally don't mind my Pin oak, English oak, Beech, Black oak,and several Nuttall's oaks having brown leaves, still. And likely several others. just mow them over in fall. I guess those in some housing authority run neighborhoods, have reason to complain. Poaky1

"how long do oak leaves fall"
I suppose it depends on how far up from the ground they are, and whether or not the wind is blowing when they fall. ;-)
I don't like any tree where the leaves hang on past the Fall. I want to get any raking up over with as soon as possible. Who wants an untidy garden all winter long? Raking up leaves when the Crocus are blooming in the Spring is the pits. Russet colored is just a polite term for dead brown in my book. How do your neighbors feel about it? They get your leaves too.
Mike

Thanks for all the replies (and sympathy)! Yes, I do mow them but there are just too many leaves so I must rake as well. I don't have a leaf blower. I try to stay on top of them for my sanity - no neighborhood association to worry about, and nice neighbors, too! I totally agree with Mike - who wants to still be raking dead leaves when the bulbs are coming up? On the bright side, I never lack for mulch :)

I am kinda bored here, so I will just add that i wish I had more leaves than I do. I will have plenty in a few years. I like to make compost. I used to go collect folks fall leaves at the leaf dump. This is the first year for a while which I haven't done it actually. In my last post I meant to say to mow them over in spring, but I said fall. But if you mow them over in spring or fall and add kitchen peelings of fruits/veggies and mix with a garden fork or use a tumbler, you can add to your garden to improve your soil. Sorry if you already do this, or know about it but don't wanna do it. Just figured I'd add that idea. It helps create the "humusy soil" that some plants seen to favor, For some adding peat moss sparingly helps also. I know this is the tree forum, but some shade plants for under these trees appreciate leaf mold and composted organic material etc. Poaky1