It never fails, every spring the same story unfolds. Just when warm spring weather seems to be the norm, a sudden cold snap will hit wiping out all the early blooms. But we don’t have to play the victim to this recurring tale; there are ways to protect the plants in the garden from untimely visits from Jack Frost.
To protect blossoms on shrubs like azaleas that are in full bloom spray them with a light mist of water, and then cover them with plastic sheeting. In effect you are creating a little greenhouse without any ventilation. Just make sure you remove the plastic before the sun heats things up in the morning.
Cool weather crops like lettuce, onions, broccoli, cauliflower and English peas, shouldn’t be bothered by a light frost, but need protection if extreme or extended periods of cold are in the forecast. 
You can cover them with plastic milk cartons or, if you remember how to make them, those funny little newspaper hats you created as a child are great for protecting young plants. Just place one over the plant the night before, and pull some earth up around the corners to help anchor it. Again, it is important to remove any covering from the plant before the day gets warm.
Now, one last thing. Never let your young transplants go through a cold night dehydrated. Make sure they are well watered before the sun goes down.
With these tips you don’t have to let an untimely frosts ruin your garden. Just give your tender plants a little extra, temporary protection.