Summer_Squash, it appears to only be the old leaves. The further down the vine I go, the better the leaves look. I just checked. Some of the decaying leaves do also have yellow spots on them. And I found two very small but already dead/yellow fruits. This post was edited by wstoutamire on Wed, Jun 25, 14 at 13:41

I had a similar-sounding problem where small patches of my squash (and tomato) leaves were becoming brownish. A friend suggested it was spider mites, so I took a hose and sprayed a strong jet of water on my plants. It seemed to stop whatever it was.

Browning of the *lower* leaves seems to be a normal occurrence with some cultivars of clematis. It usually happens in the heat of the summer after blooming time. Current knowledge suggests there is little that can be done other than to make sure that the plant is well watered and has a thick layer of organic mulch around its base to conserve moisture. Just prune away the dead leaves and leave the vines alone. Many times the leaves can just be crushed and they will fall away. Another type of browning leaves happens when the plant, or part of the plant, has suffered from 'wilt' and that portion has died. In this case the brown leaves extend to the growing tip and the vine becomes very brittle, almost black, and the axil buds are also brown or black. It takes some experience to determine whether this portion is dead. If the tip is bent and it snaps off cleanly, it is dead. Prune this down to either a living branch, live leaf axil, or to the base. The plant may be dormant for a period, but if kept well watered and fed you should see new growth shoot either later the same year, or the following year.

OK, good info, thanks! I don't use regular potting soil any more. I found it did retain too much water. I use SEED STARTER soil now. It's much finer and drains better. I also don't use that big of a pot. I got 16 oz. clear plastic cups. Punch a good size hole in the bottom of the cups for drainage. Fill the cups about 3/4 full with the starter soil and wet it. I wet it a couple of times until I see that the soil at the bottom is damp. You can tell by the color. It will darken when it's wet. Then I let them sit over night to drain any excess water and for the water to distribute itself evenly. Then I take my cutting and very gently scrape off the green outer bark to expose the white layer just under the skin. Some people also will just slice the bottom at a very steep angle to expose that inner layer. Dip it into some type of rooting hormone. Before sticking it in the cup take a pencil and make a hole in the soil first. Then you can stick the cutting in the soil without rubbing off all the hormone. Pat the soil firmly back around the cutting. Now you can water them in fairly well and let them drain. I put mine right out in the sun, uncovered, in my little seedling nursery. I keep a close eye on them for water. With the clear cups you can see all the way to the bottom so you can see when the soil looks dry down there. Like I said the color will lighten as it dries out. Keep them evenly moist all the time but not soggy. Outside it's hard to give you a specific time table of how long that will take because the heat and humidity will play a part in how long they take to dry. I usually water at least every other day here (unless it rains) in the summer even though it's humid here by the lake. But I only water them a little bit at a time. After the initial soaking at planting time I let the top of the soil get a little dry before I water again, like maybe and inch down. The other really nice thing about the clear cups is that you can see when they have rooted! You don't have to tug on them or disturb them in any way to know if they have rooted or not. Surprisingly the roots seem to head for the light at the sides of the cups right away. I let them stay in the cups until the bottom of the cup looks pretty full of roots and then I transfer them up into 1 gallon pots. Hope that helps and if you have any questions please ask! Don't feel bad about not having much luck at first. I killed dozens of them before I found this method that seems to work pretty well for me.