I am a newbie veggie gardener, gardening from a VegTrug on my roof deck. I have squash and zucchini plants that looked great until about a week ago, but now the leaves are yellowing and dying and the small squash, about 1.5" long and browning and shriveling up.

I read about blossom end rot, but it sounds like this might impact the fruit when they are larger. I also read that the plants need about 1" of water per week, but don't really know how to tell if it's getting too much or too little. The surface, about 1" deep, is relatively moist, but I'm unsure if this is making its way to the roots.

Should I water until it comes out the bottom of the VegTrug? And ideas how to stop the squash from dying?

Thanks!

Here's a list of yellow leaf possibilities:
http://www.gardeningknowhow.com/edible/vegetables/squash/why-squash-leaves-turn-yellow.htm