Plant ToesBryn Wallace

6 Tips to Overwinter Your Containers

Just before the first hard freeze occurs, usually in the first half of December it’s best to start protecting your containers from oncoming snow, ice and freezing temperatures. For gardeners, the containers we purchase as well as the plants we grow in them are an investment worth protecting, whether we use stylish ceramics and concrete, durable resin pots, or traditional terracotta. Some pot materials are more durable than others, but there are many ways to protect all types of containers from frost, ice, and snow so that they will last for many years to come. To help you, we’ve assembled a guide for overwintering your pots and vessels.

The Most Durable Materials for Winter Conditions

If you are looking for materials that can reliably withstand winter temperatures year after year, resin, durable plastic, wood and concrete containers are some of the best types to select.  Winter damage to containers most often means cracking, and pots generally crack because they absorb water that can freeze and expand, causing damage.These materials are the least susceptible to cracking during the winter, as they either do not absorb water at all, or they are resilient to freezing and melting water. If you plan to leave your containers out year round and want the least work possible involved in maintaining them, these 4 types of containers will work well for you.

Protecting Other Types of Containers

While durable plastic, wood and concrete are your most winter durable materials, they may not match your aesthetic preferences and they may not be the types of containers you already have. Thankfully it is very easy to protect containers made of other materials. Ceramic and Terra Cotta are both beautiful materials for containers and can easily be kept in excellent condition for years to come by taking a one or two steps to prevent them from cracking in cold weather. 

A note on Talavera (also called Mexican Pottery): This is the one type of ceramic that you really must bring indoors for the winter. This beautiful pottery is created in a warm climate, for a warm climate. It is not readily able to withstand the conditions of a Virginia winter, and is much more likely to crack and break than other materials.

Place the Plants on Plant Toes or Stands

Most of the time, a cracked and broken container has absorbed moisture from the bottom of the container where its base comes into contact with the moisture filled ground, deck or patio. The key to protect any container is to keep it out of contact with water, so that it cannot absorb it. The easiest way to do this is to purchase pot feet or pot stands. You can purchase Down Under plastic plant stands ($19.99) or Bosmere pot toes ($27.99) here at Merrifield as well a variety of pot stands designed to match any number of container colors and materials. Down Under Plant stands can be cut to fit underneath whichever container you need to support, keeping the stand nearly invisible and your containers elevated safely above any water that may collect on the ground beneath.

Bring Indoors, Turn Upside Down, Elevate

When your containers are empty of plants and potting mix, any of these tactics can do the job. Bringing your containers inside is the safest option, and highly recommended for Talavera pots. The primary goal, as with placing your containers on plant stands, is to keep your containers away from moisture. Some people bring their unused containers into their garage or shed, others turn them upside down, elevate them above the ground and cover them with a waterproof tarp. There are many options! Try the method that works best for you, based on the amount of space you have available.

Protecting the Plants inside the Containers

Up to this point, we’ve discussed the primary ways to protect the container, but not the plants that you may have planted in them. Plants left in containers through the winter do need some extra care, since they lack the extra insulation provided by the ground. The tips below address some important steps you can take to keep your plants safe through the winter when they are growing in containers.

Insulating Pots to Protect Plant Roots

If your containers are hosting plants throughout the winter and if you want to leave your containers outside during the winter, you can protect them by wrapping bubble wrap around the pot to insulate the plant’s root system and vessel to keep it from damage due to wind or frost. As bubble wrap is not very attractive in the garden, you can spruce it by wrapping burlap around the container up to the lip of the vessel, securing it with pins. You can even add a string bow around the burlap to secure it and make it look attractive throughout the winter season. If your container is on a balcony, you can also cover it with a DeWitt frost blanket or Harvest-Guard frost cloth, both of which we sell at Merrifield Garden Center. The frost cloths come in different sizes, including 5’ by 25’ ($29.99), 5’ by 50’ ($59.99), and 10’ by 15’ ($22.99) as well as a thicker frost protection blanket ($34.99).

Plant Containers into the Ground

An old school method for protecting your containers throughout the winter is to dig a hole and plant your vessel directly into the ground where it will benefit from the soil’s insulation and will be protected from wind and other winter damage. The pot should be planted with just a bit of the lip visible. If you use this method, the plant will enjoy being in the same soil as other plants surrounding it. You can insert a label into the ground to remind you that the container is planted in the soil below. You can cover the top of the container with soil or mulch to increase the insulation.

Bring Delicate Plants Indoors

An easy way to make sure your expensive pots and containers are protected from winter damage is to bring them indoors for the season, as long as they are light enough to carry. You should move the containers into an unheated garage, shed or basement and make sure to check the soil’s moisture frequently over the span of winter. The plants that will be stored here for the season (like begonias, geraniums and hibiscus) don’t need very much light as they will naturally go dormant until the spring time. Your plant material and containers will be just fine if placed in a dimly lit basement or garage.

Group Plants Together

A good way to make sure your plants’ containers don’t break or get damaged throughout the winter is to group your small containers together and wrap them all with bubble wrap and burlap and place a frost blanket over top of them. Keeping these smaller plants together will make it easier to cover them all at once. These containers should be lifted above the ground with plant stands or toes to keep the moisture from gathering at the base of each vessel.