Survival Guidelines For Your
Containerized Plants in Cold or Freezing Temperatures

You can be successful with outdoor plants during colder temps. Winter container garden guidelines are rather simple.

A rule of thumb for cold hardiness in a container is to DEDUCT one zone, or to really be on the safe side, DEDUCT two zones.

A generally accepted guideline for hardiness in a container is to deduct one zone. In other words, a plant hardy to Zone 5 might only be hardy to Zone 4 in a winter container garden. Again, this is a guideline. There are a number of factors that affect the cold hardiness of individual plants, some of which are length of exposure to seasonal cold, water availability (drought stressed plants are more cold tolerant), how recently they were planted or repotted, etc.

Above ground planters should be considered to be one or two zones colder than the same plant in the ground because there is little insulating the roots against the cold in containers unless they are buried in the ground.

Not sure of your cold hardiness zone? Click here for: Cold Hardiness Zone Maps

Winter Container Garden Freeze / Thaw Issues

Yes, a container can freeze and thaw HARDER AND QUICKER than the soil in your garden beds. This presents a problem for the survival of the container's plants. You need to help reduce the potential freeze/thaw cycle that can hurt the plant's roots.

If you have perennial plants that you are worried about "not making it" through the winter, you've got a few options. Of course one is to bring the container inside to a protected area. Many gardeners will bury their smaller containers in their garden beds. I sometimes do this, especially with terra cotta pots. This protects not only the pot itself, but the plant. I sink my pots down to the bottom of the rim.

Some of my planters that are made of plastic or resin are left nestled in a corner of my garden, protected from wintertime winds. (I'm in Zone 7a, by the way.)

However, whether my containers are terra cotta or plastic or resin ... there are some that I put into the garage for maximum protection. It completely depends upon the exact plant that is in each container. Some plants just need more protection than others. I have to say this is where your knowledge of each plant's characteristics and growing needs comes into play.

Never hesitate to research each plant's specific growing needs, temperature requirements, etc. You'll be glad you did  :-)

Many gardeners will go to great lengths to wrap/cover exposed containers. Let your common sense dictate what the plant AND your container needs for protection based on the cold hardiness zone where you reside.

Protect planters that may crack during freezing temperatures. Learn what you need to consider regarding the freeze-vulnerability of the different materials gardening pots are made from. Please read my article: Container Winterizing Tips

Winter Container Gardening – Plants for Adding Color

There is no reason to leave your container gardening efforts tucked away during the colder months. Yes, hard frosts do kill off all our summer annual flowers and plants. But, planting a winter container garden is possible by using plants that are cold hardy and tolerant of temperatures that can get below freezing.

As always, know your planting hardiness zone. But, you'll find that local nurseries and garden centers carry cold tolerant plants for your zone, and they should survive quite well for you in planters.

As An Example, These Are Some Proven Winter Favorites
That Will Add Interest And Color
To Your Garden During The Colder Months

Annuals that love the cold:

• Pansies

• Violas

• Panolas: (a cross between the reliable winter flowering pansy and viola; has larger flowers than violas)

• Flowering kale and cabbage

• Some lettuce and spinach varieties

Perennials that you can containerize:

• Hellebores: Christmas or    Lenten Rose

• Smaller shrubs, hollies, etc.

To easily view ALL the projects and how-tos I've got to share with you, please go to my Site Map and take a look. You might just find a few things that catch your eye.
Your garden will thank you! Site Map

Please keep coming back — I'm adding more projects
all the time :-)