That sounds familiar to us last year, but we figured it was the heat. This year it is the exact opposite, we have had it running out our ears. Tonight I picked an 18 gallon tub full. We plant every 4 weeks. I noticed some blooms on the 3rd planting, but we are still picking from the first and second plantings too! The first planting is looking rough, but I am fine with that.

Maybe hit it with some fertilizer, that always seems to help.

Jay

What would do best on that? I can push out 9-15-30 or 20-20-20, or the way we did it a few weeks ago, which came out to basically 14-17-25.

Are they being pollinated?
I have one mature 48 foot row and one of younger. I have been picking 1.5 bushels per week which is lots of pounds! It will slow down later and that is why I have the second row.

Are they planted on black plastic? If so, could their roots being getting too hot? Don't know, just asking. do you find that the older plants slow down in producing?

Yes black plastic. They have only put off 1 cutting and it was good production for first batch. Maybe 3/4 bushel of 8ish inch zucinni little bigger than a half dollar. That was last Tuesday.

Mine's slow too, I don't know whether it was the heat (on and off until the heat wave last week) or all the rain we had in June (and the accompanying lack of sun). Now I'm hoping I can harvest more than 6 from the dozen plants (got 4 transplants that are really small, I moved them rather than chopping them when all 4 seeds in hill sprouted) before the SVB get them.

Early Prolific yellow squash is even slower this year.