We had a couple of days of temperatures that were low enough to damage or kill some plants.
With more cold weather likely, it's a good idea to keep plants well-watered, which will help them withstand lower temperatures a little better. If it's predicted to fall below 40 degrees, you may want to cover some plants.
The winter temperatures this year have been a bit warmer than usual, meaning that any of the more tender plants that have put out new growth may get damaged if the temperature falls.
If plants need covered because of cold weather, keep a few things in mind. Temperature fluctuations and the day's length prior to a freeze affect a plant's ability to withstand freezing temperatures. A gradual decrease in temperatures increases a plant's ability to withstand the cold. A sudden temperature drop usually results in more damage. Short periods of warmer weather in midwinter also make it more difficult for plants to adapt to cold temperatures.
Cold injury can affect the entire plant or to just parts of it. Fruits and roots have little ability to acclimate to cold weather and this is one reason containerized plants may be more susceptible to cold injury then those that are in the ground.
There are some things to do before a freeze to protect landscape plants. It may be too late for this now, but as you plant new material in your yard, remember to select the proper plant and the right location. The microclimate of a location is determined by factors such as elevation, landform, surface reflectivity, soil type, degree of canopy cover, and proximity of structures or other plants. Within your landscape, there are many different microclimates. Be aware of these before choosing plant material.
Tender plants should be planted in an area with good air drainage, not in a low area where cold air settles. Arrange plantings, fencing, or other barriers to protect tender plants from cold winds. They may still need to be covered. Don't use plastic to cover plants and make sure the entire plant is covered down to the ground.
If you had cold damage from our low temperatures last week, don't cut off the dead parts just yet. Any type of pruning will force new growth. This new growth is susceptible to cold injury should our temperatures drop again.
It's hard to leave damaged plants in our garden but unless you are sure they are dead, leave them alone. The plants I knew were dead — sun lowers, pentas and vincas — were removed. These plants self sow, so when it warms again, the seeds will sprout and soon add color to the garden. A little patience now will be good for our gardens later.