There's a possibility temperatures will reach a record low of 21 degrees tonight and that could adversely affect some plants in the garden. Don't panic though, most of these plants have seen this many times over the years.
Lets start with things we're not worried about and/or couldn't really protect anyway. Most shrubs and trees will be fine. Things like azaleas and rhododendrons shouldn't be affected along with dogwoods and pines. Magnolias and fruit trees might get the worst of it. In my garden, both are too big to do anything about, so all I can do is cross my fingers. If the magnolia has started to bloom, flowers might get zapped and if not, the buds stand a chance of freezing out.
For spring blooming bulbs, I won't do a thing. They have been through this for centuries, worse case scenario there will be some bud blast and loose the blossoms for the season. This is most likely to happen on daffodils.
I'm not worried about pansies or violas either, they should be able to take the cold.
Most of what I'll be protecting is in the vegetable garden. Peas and greens like lettuce, arugula, spinach and more won't be killed by these temperatures, but will be happier with a little protection.
The easiest thing to use is a floating row cover. It's a spun bound translucent fabric which is so lightweight, the plants themselves can hold it up.
Since soil temperatures have warmed up, I'm not too worried about one night of cold. We should reach 50 by tomorrow afternoon. Lets hope that's the end of the really cold weather, but don't forget, we'll get frost all the way through May.