Heat wave!

As you may know, we're having a bit of a heat wave here in SC. It's 100 degrees with a real-feel temp of 103 for the fourth day in a row, and things aren't supposed to cool down any time soon. I know, those of you who live in desert regions are probably laughing because it's only 100 here, but in this climate, these temps are sheer misery.

Anyway, since summer is nearly officially upon us, I'd love to hear from experienced square foot gardeners about how they handle keeping plants from extreme stress under such conditions. Mulch? Shade? Mist? A combination of the above? Or maybe Mel's mix is moisture-retentive enough to take care of things even in such hot weather? Have you found that daily watering is sufficient? If you use shade fabric, what do you use and where do you get it?

I'm concerned that too much watering will wash away nutrients from the beds and leave the plants without what they need to complete the growing season. True or false?

I think it's true that you can overwater the MM in that nutrients will be flushed away. That being said, if its so hot you have to water multiple times a day it may be beneficial to feed the plants liquid nutrition if they start showing signs of deficiency.

I have to water 2x/day on many plants. Also, someone mentioned you can prune the lower leaves on tomatoes to help prevent splash back type funguses, so I trimmed my plants today.
I did find some pinestraw mulch at the local nursery and I put it under many of the tomatoes. It seems to have helped.

Wal-Mart sell the rolls of shade cloth. If this 100 degree weather persists, that may be my next move.

I also have removed the lower leaves on my tomatoes. They look kinda funny, but if it prevents leaf spot and early blight from setting in, I can live with their legs looking kinda nekkid! I haven't put down any organic mulch, but some of my tomatoes are planted in red plastic mulch and some have tomato watering trays.

This is my first time using watering trays. I didn't think I'd like them, but so far I do. I ordered red rather than black trays because I thought the black ones might make things a little too hot during a South Carolina summer. The trays are a little larger than one foot square, so where I set in one tomato plant per square, I trimmed the edges with scissors to make them fit. They completely cover the Mel's mix under each plant. Watering either by hose (gently) or bucket and cup is ultra-easy with no splashing -- and even if you did somehow splash, the water wouldn't be coming into contact with the soil, so the plant wouldn't get hit with soilborne disease.

The trays have four funnel-shaped points that you press down into the soil, and that's where the water poured into the tray seeps through to the plant roots. You're supposed to put granular fertilizer in the points, but I haven't done that yet.

Just as an aside, my plants' roots are probably cooler than we have been for part of the past 24 hours. My husband got home yesterday afternoon to find that our air conditioning had stopped working. By the time I got home from work, it was 93 degrees in the house!