I'm not going to say for sure, but you said that you foliar sprayed... It's odd that if you treated both plants the same that the leaves of one are worse than the other... but the damage is so isolated to the leaves that I can't help thinking that the problem was with the spray.

Is it possible that the spray bottle had something else in it before the fish emulsion?

Also, I'm growing the same variety, and I wouldn't call it a 'goner', it's a very vigorous zucchini!

I rinsed out the bottle before I sprayed so I don't think that's the problem. Also the brown edges were there before I sprayed; they just accelerated. I hope they do come back, but they've been heading downhill for several weeks. We've had lots of rain but as you can see they are in a bed with solar mulch so I don't think they are drowning.

Oh, and this is obvious I suppose, before you plant anything in that bed... maybe a soil test?

That is a handy pdf, thanks. I did have a soil test and made some amendments this spring but they were light. Azomite is a mineral but is supposed to be slow acting and I've read it's impossible to use too much (although I used much less that bag recommendations). It's a mystery. Seems like there's one every year. :)

Could that black plastic be cooking the roots?

Nope, it's solar mulch from Johnny's. I've used it for years with great success.

Just a thought. :)

It was a good thought, Peter. I've been wondering if it's too hot or too cold, too wet or too dry, but I can see my how other plants in other beds are reacting, and so I don't think that's it. I'm inclined to think it's the amendments that I added this spring - some sulfate of potash and a bit of sulfur - but they were in such small quantities it's hard to believe they'd do this much damage . . . and I added them to all the beds and most other plants are doing well. Squash usually grows like gangbusters this time of year.

vickima(z5 MA) said:
"I rinsed out the bottle before I sprayed..."

Exactly what was in this bottle before you rinsed it?

A weak solution with spinosad

You could have over fertilized it with all that stuff you put on it.

I didn't think I added all that much, but I'm inclined to agree that it's probably over-fertilization, perhaps too much phosphorus. I've looked online for similar symptoms in squash leaves and haven't been able to find anything.

Do you have squash bugs?

No squash bugs . . . yet.

The yellowing and crispy leaf edges in the second pic look like classic nitrogen burn to me.

Dave

Thanks for that link rgreen!

I have 5 crookneck plants. Four took off and one remained the same size for about a month. The leaves looked similar to yours and appeared to be almost 'petrified'. New buds that never grew/opened, almost as if it was a plastic plant. It was not my soil as I dropped in an eggplant that is doing just fine. I was speaking with a horticulturalist and they said that sometimes a plant just doesn't take for some reason. Not the most scientific of explanations, but I suppose it could be apropos at times.

Jim's, your suggestion is my favorite so far which I paraphrase as "sometimes a plant just doesn't grow." But in my case I suspect it *is* the soil. I planted a couple more squash seeds there; curious to see what they do.

Let us know what happens.