Possible frost?

Possible frost?

Zone 6, St. Louis area We had an outrageously early spring (and barely even had winter) and many people in the area jumped the gun and planted their gardens already. Including me, despite growing up with the rule of planting your stuff outside around Mother's Day. Now the weather forecast is showing a possible low of 32 degrees Sat. night, so I'm worried about frost. (Weather forecasts around here are notoriously inaccurate, so it's not set in stone.) If this prediction comes true, what do I need to do to protect my newly planted garden? I have the usual stuff of tomatoes, eggplant, bell peppers, cucumber, melon, lettuce and a bunch of herbs. Would an old sheet or two over the garden be appropriate?
Our 2010 Garden

Our 2010 Garden

the kiddo and i

the kiddo and i

pictures and a few questions

pictures and a few questions

curtain advice

curtain advice

a few of my favourite things about my room

a few of my favourite things about my room

Raising Existing Beds

Raising Existing Beds