Terracotta pots are a staple of many gardens up and down the country and a beautiful way to bring life and colour into your yard. Terracotta is known to be particularly susceptible to frost, so you need to make sure your pots are properly protected before it’s too late!
Once there is permanent damage, there is nothing you can do to fix it, so prevention is definitely better than cure so frost proofing your terracotta pots is a must!
Why Does Frost Cause Terracotta to Crack?
Primarily, there are 2 reasons why the frost will cause your terracotta to crack, and they both involve water and how it expands as it freezes.
Firstly, if your pot becomes too saturated and freezes solid, there is a good chance that the water will expand therefore cracking the whole pot.
Secondly, terracotta itself is a porous material and will absorb moisture, so if the temperature falls below 0°c for just one night, the water can still freeze. When the water freezes, it will expand, and this is what will cause your pot to chip or crack and break.
Frost Proofing Terracotta Pots – 5 Top Tips
There are a few different things that you can do to help make your pots hold firm during those colder months, read on and we will have a look at how to frostproof your terracotta pots.
Take Inside for Winter
The first and best method is to take them inside once the weather becomes too cold and keep them inside for the winter – you can take them back outside for the odd day/ week if the temperatures are going to remain high enough.
Your pots can be stored anywhere with a roof really, this means a shed, an outhouse, a greenhouse, a conservatory etc.
First and foremost, this will keep your pots mostly dry so that they do not absorb as much moisture and depending on where you are able to store them, the temperature is likely to stay above freezing.
The only downside to bringing your plants indoors is that they can be quite heavy and also take up a lot of space so this option will not suit everyone.
The next way to protect your terracotta from frost is to apply a waterproof sealant all over (inside and out).
As we previously mentioned, it is the expansion of the moisture as it freezes that weakens and cracks the pot so ensuring that the pot is sealed and watertight means that the pot can remain outside in all weathers.
A clear watertight sealant (amazon link – opens in a new tab) is best used on new pots before use and then reapplied every 3 to 4 years – this means that this option may not be suitable for all plants – especially those that do not like having their roots disturbed.
For those that like to see their terracotta become weathered very quickly, using this powerful water sealant is probably not the best thing to do. Applying this sealant will mean that achieving that aged and weathered look will take a little longer.
A good idea to protect your terracotta from frost is to insulate it to try and prevent the water from freezing in the first place.
You can wrap your pots in hessian, geotextile blankets or thermawrap general purpose insulation (amazon link – opens in a new tab).
Mulching with a layer of straw or shredded leaves will also provide much-needed insulation and help prevent the soil from freezing.
Insulating your pots to keep the temperature above freezing does work, although you may want to remove the wrap during warmer days as the insulation can also prevent the soil in the pot from warming up when the sun comes out.
Bubble wrap can be used to insulate your pots and although I have not tried this myself, it has been recommended to me many times before.
The benefit of bubble wrap is two-fold. Not only will the little air pockets add a layer of insulation but when used on the inside of the pot, it also provides a little room for the expansion of any water in the event your pot freezes solid.
Personally, I have had a great deal of success with the methods already mentioned, but I may give it a go in the near future so I can update you with my own results.
Another tip to help frost-proof your terracotta pots is to keep them off the ground a little.
You can do this by making a small polystyrene base, using a small piece of wood with some drainage holes, you can use almost anything as long as it does not hold any water and allow it to pool.
This little tip will not be enough on its own to prevent frost damage but if used in conjunction with one of the other methods above, it will help prevent your pot from absorbing any more water than is necessary.
As we have mentioned, the cold itself is not the cause of the damage to your prized pots, but the water that is in the soil or absorbed into the terracotta itself.
Ultimately, the method with a 100% success rate of frost proofing your terracotta pots, is to get a roof over their head and bring them inside although this is not ideal if you are short on space or are unable to move the pots yourself.
Applying a sealant will help protect from water damage and keep the pot sealed during freezing periods as well, although it may take longer than usual to see that weathered look that you’re looking for on new pots.
In addition, wrapping/insulating could also be an effective method of protecting against frost by preventing the pot from becoming completely frozen. Depending on how cold it is likely to get where you are; unless you are taking your pots inside, we recommend that you try one or more of the other tips together to increase your chance of success.
Garden Doctor Tips
“Keep pots off the ground and especially away from areas with standing water!”
“Sealing the outside of the pot alone will not suffice, you will need to seal the inside too!”
“If you are to leave your pots outside, a combination of sealing and insulating will yield the best results!”
“Where possible, keep your pots as dry as possible, it is the water that actually causes the damage and not the cold!”
Frequently Asked Questions
Are terracotta pots frost-proof?
The short answer is no, terracotta pots are not frost proof. However, terracotta pots can be used outside during winter as long as it is unlikely to freeze, or you have taken precautions to prevent frost damage.
Why are terracotta pots so expensive?
Unfortunately, good quality terracotta is expensive. Terracotta is extremely heavy, and the cost of logistics will have to be factored in alongside production costs.
How do you winterize terracotta pots?
The best way to winterize terracotta pots is to keep them as dry and as warm as possible. This means you can either take them indoors, insulate and mulch and apply a watertight sealant.
Hi, I’m Trev and I’ve been growing things since I can remember. When I was younger, I grew up on a farm, so I have always been around plants and animals. After studying horticulture at university, I decided to start my own nursery which I have run now for 25 years. In my spare time, I run this website – which is a resource for people who want to learn more about their gardens.