Sounds like an insect problem.

Green options: Soapy water insecticide. Just dilute soap and spray it on the laves. Or, cover it with netting.

Chemical option: Sevin. Get some at the hardware store, sprinkle it on the leaves.

Personally, when a plant gets that bad I hit it with Sevin.

Not to snap too quickly at flame bait, but Sevin is highly toxic. There are plenty of safer alternatives if you do want to use an insecticide.

It sounds like your plant could be suffering from overwatering, which can cause leaves to suddenly droop and turn yellow. If the container is too small or the plant is root-bound, you could see similar symptoms.

That wouldn't account for the holes, though. Can any pets get on the roof? Are more leaves getting eaten each day? Could your building have mice? Have you seen any caterpillars in the trees nearby? Damage like this sounds like slugs, but they're unlikely to get on a rooftop. Try checking on the plant in the very early morning, around 3 or 4 am, to see if you spy any nocturnal critters.

If the holes are in the middle of the leaves, that implies insect damage to me. Most chewing insects would stay in the vicinity of your plants, either on the underside of the leaves or even hidden in the soil or mulch.

No bird droppings around the plants, are there? The damage doesn't sound like birds, but I suppose anything's possible.

I wonder if squash bugs could be the culprits? It's impossible to identify many insects by the damage alone, but these buggers do cause wilting and they fly. I'd think they'd stay somewhere around your plants if it's them though. Keep checking for eggs on the undersides of the leaves. Most chewing insects lay their eggs right on the host that will feed their young.

I've concocted an insect repellent for cases when I don't know what's causing the damage, though I'm sure it doesn't work on everything. I don't intend it to kill anything but just repel many insects. It includes a few drops of orange oil, a clove of garlic that's been whirled in the blender with a bit of water and the liquid strained to use, and about a teaspoon of Ivory detergent added with enough water to make about a quart.

Garlic and orange oil repel different insects, so I hope I get most of them repelled with this concoction. The "essence" of marigolds (extracted the same way garlic is, in the blender) could be added to the brew as well -- they seem to repel some insects.

For containers I spray it lightly on the soil surface as well as on the stems of the plants. So far I've intentionally avoided spraying the leaves though I think I would if I tested a leaf first and it survived the brew.

I don't spray the soil surface in my open garden with this repellent, since the orange oil is also an insecticide that kills earthworms and ants, and garlic certainly drives them out of the immediate vicinity if it's strong enough.

Good luck either identifying the culprit or keeping it at bay!

I have zuchinni's that are producing great amounts of fruits. I am getting a couple of zukes a day.
But lately, the leaves (which are huge) are turning yellow. The branches droop.

Leaves on the bottom of the stalks are turning yellow then brown, but even ones high on the stalk are getting the yellow color.

These plants are in a covered container called an Earthbox. I have two zuchinnis and two yellow squash in the box. The box holds about a lot of soil (one of the large Miracle Gro bags)
Anay, you mentioned bird droppings. The birds seem to use this box as their little box. I have a net/trellis that I had to tie the plants to to keep from falling out of the box. The birds perch on the trellis and poop all the time. White/brown/ in between.

Could this be a problem. I did not see any signs of SBs, but I will check again for eggs tonight.

I keep it well watered. DO you think it is overwatered, maybe.

I donÂt have pictures, because my camera broke, sorry.

Thanks for any help you can give.

Mine were doing great, now it looks like bugs are eating the stems. They are dying and at the bottom of the leaves near the stem it's all yellow and gooshy. It looks like bugs are eating them from the inside out. I used sevin when I first planted them but I don't want to use poison with all the bees and stuff I have around. I might start another crop and use soap and neem.

Margocostas's issue sounds like Squash Vine Borers for sure.

They do literally eat the vines from the inside out.

Squash Bugs and Squash Vine Borers are the squash lover's worst enemies. :-(

Choxie,

I am having the exact same problem - the leaves are turning yellow and those at the base are drooping, shriveling and turning brown; I have to pinch them off because they're goners. Upon closer inspection, I saw small round patches of a fuzzy white mold-like substance on the top but mostly the bottom of the leaves. Is it some kind of fungus? I feel it must be related to the symptoms. I had green aphids on the plant but have been treating them successfully with soapy water. My plant is still producing zukes, but I think this mysterious white fuzz may get the best of it.

Any ideas?

Hmmmm, fuzzy white mold substance sounds like powdery mildew, which will certainly make your squash leaves do that! Unless they were really small, semi-mobile, very fuzzy patchs, which could be a type of mealy bug... or hopper larva. Would you describe it as almost silvery? That would be mildew. Are you in an area with high heat and humidity? That fosters mildew. I think there are fungicides you can put on there, but to be honest I always get mildew on my squash each summer and just live with it. Try to not get the leaves wet when you water, that will help slow the spread of the spores. Since I usually have this problem when my plants are big, I sometimes carefully clip and remove the leaves that are effected.

Of course, PM doesn't sound like a likely suspect for the holes in the leaves, though... perhaps you have a couple seperate issues? Hope some part of this helps!

Sunni

There are two organic controls for powdery mildew (which, by the way, won't generally kill your plants -- it just saps their strength). One is a 0.5% to 1% baking soda solution (1 to two teaspoons -- not tablespoons -- per quart of water). The other is a 10%-20% milk solution (about half a cup per quart bottle, the rest filled up with water). Both techniques have undergone peer review.