Definitely don't do the saran wrap idea. It'll bake whatever does germinate in a few minutes in your climate.

If I were in your situation, I'd plant the seeds slightly deeper than the seed packet recommends (probably no more than double the depth of what the seed packet says) and water VERY thoroughly in the early morning. More of the water will actually absorb into the soil instead of evaporating.

Despite the top layer of soil drying out over the day, the lower layers should still retain enough moisture to germinate your seedlings. At least I would think so, especially if you are already watering several times a day.

When it is really hot, sometimes I will sow seeds and then mulch around the patches of dirt where I sowed the seeds. Depending on how big the plants will be, I leave a 1"-6" circle around each patch, big enough for sunlight to shine on. The surrounding area is kept cool and moist, and simply watering the patch in the morning, like mentioned before, will work very well helping seeds germinate.

My climate is likely vastly different than yours, so you results may be different than what works for me.

Aside from that, I think planting in partial shade or buying shade cloth may be your next option.

Hope I could help a little.

Thanks for your help tripleione! I know - SoCal is so specific sometimes I feel like I should always post over there in the SoCal forum - but they don't necessarily know SFG! Bah.

Okay, so what about those 1' square cages Mel talks about covered in shadecloth? Have a few on hand, keep them over the new seeds until they are established? Anyone tried this?

I hate to have to germinate and then transplant...though this might be inevitable...I had great luck during the winter sowing in place - and seem to have bad luck/no patience with seed trays.

Or damp cheesecloth laid over the seeds? Or what about sowing between paper towels to hold in a bit of water? I made my own seedtape over the winter and it worked great for keeping things in place....