Sick-Looking Leaves

Hello, novice gardener here.  I got these sick-looking yellow leaves from my Zucchini plant.  Is it lack of nutrient, too much sun, too much water or diseased?  How to fix it?  Thanks.

The little squiggles are leaf miners.  The yellow and brown could be so many things that I wouldn't want to hazard a guess offhand.

The white fuzzy spots could be powdery mildew. It's hard to tell from the photos, for me. Spraying with Neem oil or milk solutions can help control it. The squiggly lines are not harmful unless severe.

looks like powdery mildew and leaf miners to me too. Can you cut off the affected leaves or is it most of the plant? If so, maybe treat the PM, there is lots of info about treatment with milk, baking soda etc. I don't worry to much about the leaf miners since they don't seem to do much harm.
Good luck!!

I had powdery mildew on my squash a couple days ago, sprayed it with a copper spray, and it's gone. Copper is a well known fungicide.  Give it a try.  Daconil is another option.

Whatever you decide, decide it quickly.

Thank you for the information. I have ordered Neem Oil and will try the bleach and soap spray next before the Neem Oil arrival.  It has been 90+ degree for several weeks now.  Could it be too hot or too much sun that caused the brown spots?

There dead spots could be a result of the heat, but more likely a result of the mildew infection.
 Bleach will probably damage or kill the plants. Remove and trash all the effected leaves. The plants will make new ones. Try a baking soda spray  on leaves that are not yet infected. The spray is a preventative, not a cure.  You can find recipe online for powdery or Downey mildew  baking soda spray. Be sure to wet top and bottom of all leaves.

If you are using a store bought product , read and follow all label instructions.

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7406.html

https://www.google.com/url?sa=t&source=web&rct=j&ei=8pPwU8DhMMy0yASU3ILoDw&url=http://ohioline.osu.edu/hyg-fact/3000/pdf/3127.pdf&cd=7&ved=0CDkQFjAG&usg=AFQjCNEVtcPyZVHEzwJW3ZCVLVrDcM49wA&sig2=JokS1BIdMReMTfrzwahMQQ


Would you please post a wider shot of the whole plant.

Bleach?? I wouldn't use it anywhere near a plant. Please!

Ok, no bleach.  Here is a wider shot of the plant. 

Well that looks pretty good. Just remove the yucky leaves and it will look fantastic!  

What size container is that? Your plants may be a bit stressed from being so close together (I think I see about 3-4 plants?) which would make them more susceptible to disease and insects. Or maybe you're growing a small variety of zucchini?

BCFotos wrote:Hello, novice gardener here.  I got these sick-looking yellow leaves from my Zucchini plant.  Is it lack of nutrient, too much sun, too much water or diseased?  How to fix it?  Thanks.

 
Hello, BCFotos!   
Now that everyone else has already answered your questions, let me also add:    to the
    forum!

A lot of my zephyr  squash (and some zucchini) leaves have that powdery look, which I figured is mildew, and some are turning brown --maybe tomorrow (um, later, after it's light out) I'll get out there to pull & bag the icky ones--which'll also help me locate some more squash, before they turns into clubs or baseball bats--as well as do the baking soda solution, solution   .

The planter also semi-alarmed me to see. It's not only small, it is black. Either one of those things can lead to problems, but both together especially can lead to very hot soil in the summer. And, it looks like it's on a concrete surface. During the summer, we often can't even walk on our wooden or concrete surfaces, it gets so hot. All these things must be adding a lot of additional stress to the plants in that small planter, and that will always make it easier for disease to take hold.

I'm not sure how well a plant that size would take to transplanting, but I would seriously consider putting each one separately in a much bigger pot, at least a five-gallon one with good drainage, watering twice a day if necessary, and raising the pot on bricks or somehow otherwise insulating it at least a bit from the hot surface. Better yet, moving it to a soil surface. Being higher than the surrounding ground, that pot will be a conduit for all the heat from that stony surface to travel upward into the cooler air and all through the plant. A lot of heat must be funneling into that already small, heat-stressed place.

And if you can, leave enough space at the top so you can mulch heavily. That helps so much with keeping soil cool and retaining moisture. And squash seems to adore having plenty of moisture.