You pic 2 of 2 (it is the only one I could get to enlarge enough to see) is neither BER nor a pollination problem, it's disease and the surrounding dry, brown, curled leaves would support that.

Best guess from what I can see in the picture is CMV - cucumber mosaic virus (which also infects squash) but that is just a guesstimate. The link below provides ample info that you can compare to your plant. Hope this helps.

Dave

Here is a link that might be useful: Disease of Squash and Cucumbers

Looks like overwatering to me, something that wouldn't be hard to do in an Earthbox since the soil really never dries out if you keep the reservoir full. Try letting the soil dry completely out in between filling it and I'll bet you'll get some squash.

I would be more inclined to say that it was lack of pollination. Obviously we have differing opinions ...Have you figured it out yet? Sometimes early in the season, a squash will start to grow and then just sort of wither/rot away and it usually means it was not fertilized.

I also disagree with the suggestion of virus. Could simply be the excess moisture.

As for the squash not developing, you can hand pollinate to decrease the failures.
Check the FAQ http://faq.gardenweb.com/faq/lists/cornucop/2003081901015268.html

Here is a link that might be useful: the FAQ

I would lean towards poor pollination. I have seen it often with the early fruit lacking the male blossoms. The pollination may not be taking if too humid/dry or inadequate pollinator visits; some vining species do require frequent visits.

It is not unusual for some leaves to die as nutrient reserves are withdrawn to feed the seed development phase. Hand pollination is as simple as removal of a male blossom, shed the petal and rub the stamen (male) in and around the Stigma (female). You should see the stigma turn brown within 24 hours after pollination. In this process I remove the male from another vine. (I grow heirloom and desire the genetic diversity of cross pollination amongst identical variety plants.)

Here is a link that might be useful: Pollination of Vegetable Crops

Thanks all for the suggestions. I have tried the hand pollination on the last group of summer squash I grew (which had similar problems) and had some success. I was hoping to have more pollinators around now that its spring and have seen a few bees around my plants but still being in the suburbs probably doesn't help much. About the overwatering issue-I thought that was supposed to be a benefit of the earthbox, that it couldn't be overwatered? But I will say, the soil does appear fairly moist. Has anyone with experience with earthboxes, etc found that they can be overwatered?

The great thing about earthboxes and similar containers is that they will supply consistent moisture. How moist/wet soil is depends on the soil/mix you used. A moisture control type potting mix would probably be a little wet but I think you should still get good squash.

What kind of potting mix did you use and did you add the dolomitic lime as recommended?

Oh I see. I believe I used the Jungle Growth Vegetable potting mix. I didn't add the dolomitic lime since the potting mix said it was made for vegetables... in hind sight it probably would have been a good idea to follow the directions better. Is it normal for the older leaves on the squash plants to die off as the plant grows? All the new growth looks healthy but the leaves closer to the plant are drying up - I assumed this was normal but with the suggestion of a virus now I am curious.

I have no input on the specific ailment/disease/pest that you might have but I know that in general it is a good idea to grow vegetables at the right time of the year for each vegetable. Unless you are in the southern hemisphere (then it is to late to start squash now) you are growing squash at the wrong time, even for zone 10. My volunteer squash just sprouted here in 9b, so unless it is a watering issue (no experience with your container type) your squash should start doing better soon, as it warms up and the weather becomes squash weather.

We have a large garden and grow most of our food, and lots of squash and other curcubits, but unfortunately the hubbard type we tried last year never made it (we did not get female flowers until November! too late!). I am thinking maybe Southern California does not get long enough days in the summer to grow certain things. Could that be? I got one squash out of another C maxima, I think it is a Kuri squash. You don't say where you garden, if you are near me, I strongly recommend the C moschata Butternut squash, they do wonderfully here.

To answer your last question, it is normal for the older leaves to die out, no worries there.