Stop Replacing Cracked Pots Every Spring – Expert Tips for the 5 Best Frost-Proof Containers (Plus The Ones to Avoid)

Containers, troughs and planters are an easy way of keeping the garden looking interesting through the coldest months of the year. But the down-side of including containers in our winter gardening ideas is that pots can crack and split when the weather turns very wintry and hard frosts hit.

This is especially so if you live in colder zones where the best winter plants for pots and borders need to be robust enough to handle extreme cold. Yard planters can be damaged in cold weather due to the 'freeze-thaw cycle’. In freezing weather, the moisture in potting soil freezes and expands, putting pressure on the container.

As the temperature rises and falls through winter, the moisture thaws then re-freezes and this cycle exerts pressure on the container material, potentially weakening it until it gives way. The most suitable planters are made of materials that are sturdy enough to withstand the cold, or have the flexibility to expand and contract with the freeze-thaw cycle, and this article details all you need to know about the best ones to choose.

Why UDSA Hardiness Zones Matter

The further north you are, the harder your winters will be and this will affect the choice of materials for garden containers, planters and troughs.

For example, in USDA hardiness zone 3, concrete and composite plastics will offer the best protection, in zone 4, fiberstone and double-walled resin will work well, while in frost-resistant plastics and other crack-proof materials are suitable for warmer zones.

In hot areas where you get a lot of sun, make sure your planters can withstand damage from prolonged sunshine and UV rays.

Choosing the wrong materials is one of the most common winter container gardening mistakes.

Certain materials, such as untreated terracotta are more vulnerable than others to cracking and shattering, and in this article I will look at the most appropriate materials to use if you are in a cold zone or are a container gardening beginner.

Fiberglass and Plastic Composite

Fiberglass is an excellent material. It is hardwearing and can withstand frost and extremely low temperatures without cracking.

It is non-porous and has built-in flexibility, which means it will move with the freeze-thaw cycle instead of breaking, and offers excellent insulation to plants and their roots.

Fiberglass is extremely versatile and comes in a range of shapes and finishes, such as gloss, matt and textured, to suit all styles of garden.

It can be designed to suit high-budget, contemporary designs, such as this spherical Veradek Strata Series pot at Amazon made of durable plastic-stone composite, and these modern resin cement planters at Walmart.

It can also be given a more natural, rustic appearance like this large planter at Amazon, which has a stone finish without the inconvenient weight.

I like the texture of this tapered planter on Amazon with an attractive finish, but if you are looking for something more formal, this Mayne Fairfield 20-Inch square planter available from Amazon looks very stylish.

Fiberstone

Fiberstone, also known as fiberclay, is a composite material made of clay mixed with other materials including glass and synthetic and natural fibers.

It is frost-proof, so it won’t crack or break in low temperatures, and is relatively light, making it an ideal product for urban gardening ideas and for balcony growing and roof gardens, but is heavy enough to stay upright in high winds.

Fiberclay pots are attractive and available in a range of sizes, shapes and finishes. They are often glazed and painted, or made to look like classically beautiful garden planters in materials such as terracotta.

My eye was caught by the textures of these ribbed Corso fiberstone planters on Amazon, and I also liked the simplicity of these Veradek Mason Series planters on Amazon, that come in a range of subtle colours..

If you are creating a more traditional or rustic look in your yard, or favor a cottage garden aesthetic, this terracotta Dia Fiberstone planter from Amazon might fit the bill.

This elegant shallow planter at Walmart would be perfect for winter bedding, or could be made into a patio water feature or tiny pond and for a more angular, modern look this fiberstone and clay cube at Walmart will suit a range of plants.

High-Density Plastic and Resin

If you are gardening on a budget, resin or high-density plastic containers offer excellent frost-resistance at a good price. However, always check that they are labelled ‘frost-proof’ or ‘cold-weather tolerant’.

These crack-proof materials are lightweight, so they are suitable for balcony gardens, and are easy to move against a sheltering wall or indoors when the weather turns really bad.

High-density plastic and resin are also UV-durable and shouldn't become weak or brittle after prolonged exposure to sunlight.

These materials also raise the possibility of using colours to add fun and contemporary pops of color to the yard, as with these Bloem Saturn pots at Walmart that come in several sizes and shades including purple, yellow and teal.

I particularly like the smooth contours, glaze and color range of these affordable Honeysuckle resin planter on Amazon, while these tall, stippled Worth Garden planters on Amazon will add class and elegance.

If you like growing outdoor succulents and cacti, this oval planter from Crescent Garden on Amazon has a double wall for extra insulation, while for a vintage look, these tall stone-finish, weather-resistant planters from Amazon would look good planted up on either side of a front door.

Concrete

Modern concrete planters, containers and troughs come in a wide range of stylish shapes and sizes to suit every kind of yard.

It is a strong material that won’t blow over in high winds, but it can also withstand low temperatures down to −20°F (−29°C) so you don't need to worry about it cracking or shattering.

Concrete is also excellent at retaining heat, protecting plant roots and potting soil for three times longer than other materials when temperatures drop, making it ideal for gardens in Zones 3-5 .

However, it is a porous material and will need treating annually with a sealant such as Rainguard Water Sealers concrete sealer, which is available at Amazon.

Concrete containers have shaken off their 'functional' tag and now combine durability with good looks to suit a wide range of styles.

This concrete Kante planter on Amazon has a smooth finish and comes in a rage of natural stone colours. It is durable and can withstand UV rays, making it perfect for year-round use.

I love the textures of this Wallowa pot trio on Amazon, this elegant classical concrete urn at Walmart will weather beautifully through the years while this pumpkin-shaped, ribbed pot at Amazon is minimalist and fun.

Wooden Barrels and Planters

Wood is naturally insulating unlike other materials used for containers, troughs and planters, and because it is flexible it is not affected by the freeze-thaw cycle.

It can also withstand heat and drought, making it an excellent year-round option.

Half-barrels, like this acacia wood Idzo trio at Amazon, are particularly good because their size means they can hold a lot of compost, which further helps protect plant roots from extreme cold.

This raised garden bed on Amazon could be used for growing flowers or edibles and used to start a balcony wildlife garden and this affordable hardwood double box set from Amazon has a seat where you could relax or sit while you tend your plants.

Container Materials to Avoid

To ensure the safety of your plants in winter, avoid container materials that can’t withstand the freeze-thaw cycle.

These include unglazed terracotta or clay and thin ceramic. Even if these materials are painted with a protective glaze, they can still chip, fracture or break in extreme cold, so save them to decorate the yard in summer and store them in a frost-free shed or garage in winter.

Metal containers will withstand low temperatures, but they can be labour-intensive because they are often thin and conduct the cold. Metal is also heavy, which makes it harder to move to a sheltered or frost-free place when needed.

FAQs

How Can I Protect My Pots Through Winter?

The best practical steps to protect pots from frost are to make sure they have drainage holes at their base and raise them on feet like these pot risers from Amazon so that excess water, rain and snow/frost melt, can escape.

When very cold weather is forecast, cover the potting soil with hay or straw and wrap the container in frost cloth like this winterization blanket on Amazon or bubble wrap, such as this 15ft roll available at Walmart.

Another option is to bury pots so they are naturally insulated by the soil.

Where practical, group planters together against a sheltering wall as this will slightly raise the air temperature around them.

Many modern containers, troughs and planters are constructed using frost and crack-proof materials, meaning that your yard can be full of interest and colour all year round. The snow and freezing temperatures will always be a challenge, that's why knowing how to remove snow from trees and plants will also help you protect them for the year ahead.