I have yellow squash in raised beds within 3 feet of each other. In Box A the plant is small but I have gotten one foot long squash off of it. In Box B the plant is huge and healthy and puts out squash like crazy but they shrivel and die at about 2 inches or so I haven't been able to harvest a single squash-- very frustrating. They have roughly the same soil and receive the same water. This is 'square foot gardening' so Box A has some okra planted around it - Box B is next to cucumbers and am getting a bunch of cucumbers if that is maybe making an impact. Im getting ready to just pull the plant out and replace it with something i may actually be able to eat :)

If its bigger than a tennis ball its probably not a round zucchini. Almost all zucchini sold in the US are bush type plants rather than vining ones. :-) You never know what sort of wonders might grow out of a compost pile. My volunteers this year appear to be watermelon.

I do raise melons under cover and have used the netting on pumkins/ squash when young to protect from the squash bugs. I don't use the remay or other floating row cover, it is too hot down here and as you mentioned the plants don't do well due to lack of circulation. I use insect netting that is designed for outdoor use (UV protected) and designed for use on pollination cages. I have used it on a small scale in the past and this year I am using it on a much larger scale. The netting is very durable allows good air circulation, and good sun penitration. I am using it on beans and limas, field peas, and watermelons right now. ON the watermelons I planted the first patch 6weeks before the second patch. This allow the bees to pollinate the first and st a good crop of melons. When the secound patch started to bloom and the first female blooms set fruit, I removed all the fruit then covered the first patch with the netting. This allows the bees to pollinate the second patch. I have had the first patch covered for three weeks now and I have some ripe melons under the cover so no ill effects by covering and the melons have ripened. The second patch has lots of pollinated fruit. In another week I will remove the cover on the first patch. I have all the melons on the second patch marked and any that pollinate after the cover is removed on the first patch will not be used for seed only the marked ones. This can be done with squash also. Plant two rows with on variety of each family on each row.ie one pepo one mushata etc in each row. Alternatly cover one row on day in the evening. then switch to the next the next day or in a couple of days.This allows bees to pollinate mark each fruit as it developes when a good crop is set remove all covers. I use ribbin at the base and one of those little survy flags that the utility companies use to mark underground lines. Melons under cover. Patch on right covered on left open inside one of the covers over limas

I've had plenty of bees and other little pollinating bugs so I don't think that's a problem for them (and I added a little extra help too so I'm sure they're pollinated). I did get them started late this year (because of illness), but they have been blooming well since the end of June. I think the major problem was the 100 degree heat we had for such a long stretch. It's cooled down these past couple of weeks and I've seen a new enthusiasm in blooming since then so I wonder if the extreme heat kept the female blooms from setting on. I'm in the process of setting up an indoor aquaponics system so I will be able to bring them inside and I should have my grow lights by then. Hopefully that will be enough to finish off the fruit. (And today I just saw a second unopened female bloom on the squash.) Thanks for the 5 week info. I've seen a lot of places with info on how long from seed to maturity, but not on how long it takes after the fruit starts.