Rosemary plants can live for many years under the right conditions, but if you, like me, live in an area with cold winters, you may be concerned about if your rosemary can survive. Here is the answer!
Rosemary can survive winters in most parts of the world since the plant can withstand frost. Its roots, however, cannot withstand frost, but since they are covered with soil, they will only freeze if being in extreme cold for a long period of time.
Before writing this article, I visited a local garden center where I talked to one of their gardeners with a lot of experience with growing Mediterranean herbs. I asked if she had some tips about growing rosemary in cold areas and how to help it survive the winter. I cover what she taught me in this article.
Can Rosemary Survive Winter and Frost?
The above-ground parts of a rosemary plant (stems, branches, and leaves) can survive frost, but the below-ground parts (roots) cannot.
Before writing this post, I spoke to a really experienced gardener from a nearby garden center who has a ton of experience with growing rosemary and other herbs. Here is what she told me.
Rosemary can survive winters in most parts of the world. As long as the roots don’t freeze, the plant will be fine. The plant itself can survive frost, but the roots cannot, however, since the roots are underground, the soil creates a protective layer that keeps them warm (or at least above the freezing point) unless it is extremely cold for a long time.Camilla, gardener
You can even still harvest from your plant and use it during the winter, just don’t cut too much.
Camilla, the gardener I talked to, said that it is totally fine to harvest and use some of the plant. Just be careful not to cut too much and stick to fresh, green growth to make sure the plant is fine. I can attest to that as I happily harvest from my rosemary all year and have never seen it cause problems.
You don’t even have to worry or do anything about it if the plant is covered with snow, as in the photo above. As Camilla so nicely put it, “the plant just doesn’t care”. Although I would add that if there is a lot of snow, it can be a good idea to remove it to prevent any branches from breaking because of the weight.
If you live in an area with extremely cold temperatures for long periods of time, you might want to help your rosemary a bit to make sure it makes it through the winter. Camilla also gave me some tips for this, which I cover below.
4 Tips to Help Rosemary Survive the Winter
As a native to the Mediterranean region, rosemary loves heat but is also used to cold winters. Therefore, it is best to keep the plant in the cold during the winter, so most of us don’t have to do anything to prepare our rosemary for the winter.
In areas that have extremely cold winters, however, it can be a good idea to give your rosemary a bit of assistance to make sure it makes it through the winter.
Before writing this post, I talked to Camilla, a gardener who works at a nearby garden center and has a lot of experience with growing rosemary. She gave me some great tips to help your rosemary through a cold winter.
Tip 1: Remove dead branches and stems in the fall
Dead branches and stems can increase the risk of diseases, so removing them is always good and especially during the winter, when the plant doesn’t grow much. Don’t confuse brown and woody parts of the plant with dead parts. The lower branches and stems will most likely already be brown and woody, and that is totally fine and natural. Mostly look for and remove branches and stems that are entirely dry from the base to the tip.
Tip 2: Cover the soil with mulch
Mulch can help retain water and heat in the soil, so placing a good layer of mulch on the soil around your plant can help it stay warm in the winter. Remember, only the roots cannot withstand frost. The plant itself can take very low temperatures in the winter. Straw works excellent as mulch for rosemary but wood chips and other types also work well.
Tip 3: Move your rosemary closer to your house
It can be a good idea to move your rosemary and place it up against a wall from your house. First of all, because it tends to be a little warmer than in other places, but also because the plant is better shielded from wind and rough weather. Of course, this only works for potted rosemary, but if your rosemary is in the ground, it is better protected from frost since there is more soil around the roots. Do not take the plant inside as it naturally prefers cold temperatures in the winter.
Tip 4: Cover your rosemary with a plant cover
This tip is mostly relevant if it is extremely cold for a long time since the plant itself generally doesn’t mind cold temperatures that much and especially not in the winter. However, it can sometimes be good to use a plant cover to keep the ground around the plant, and thereby the roots, from getting too cold.
Why Your Rosemary Isn’t Growing Much in the Winter
You have probably noticed that your rosemary grows significantly faster in the summer than in the winter and there is a reason for that.
Rosemary goes dormant in the winter, which means that instead of using energy on growing, it conserves its energy to be prepared for cold temperatures, dry weather, or a nutrient and water shortage. In the spring, when these threats are no longer present, the plant will resume growing.
Even though your rosemary isn’t really growing in the winter, you can still harvest and use some of it. Just make sure you only cut fresh green growth and not anything brown and woody as it might not grow back then. You should also make sure you don’t remove too much of the plant. Harvest evenly from all over the plant and don’t cut more than about 25% of it.
Will Your Rosemary Plant Grow Back After Being in Frost?
Rosemary that has been exposed to frost will usually resume growing once the frost subsides. Rosemary plants are resistant to frost, but their roots are not, so if they freeze, the plant will most likely not recover, but since they are covered with soil, they are well protected from frost.
Potted rosemary is much more likely to take frost damage than rosemary growing in the ground. This is because rosemary in the ground has more soil around it to keep the roots warm. You can read about more differences between growing rosemary in the ground and in a pot here.
Even though it is unlikely, rosemary can take frost damage, so if you suspect that has happened to your plant, you should know what signs to look out for, so keep reading.
How to Tell if Rosemary Has Been Damaged by Frost
It can be difficult to tell if a rosemary plant has been damaged by frost, as the damage happens to the roots. But there are some signs you can look out for if you suspect your rosemary has taken frost damage.
The first signs a rosemary plant has been damaged by frost are stunted growth and that the plant will begin to turn brown and dry, starting at the tips and moving inwards.
Remember that rosemary goes dormant in the winter, so if it doesn’t grow it doesn’t mean that anything is wrong. If it doesn’t resume growing in the spring, however, it might have been damaged.
Below, I explain what you can do to try to save your rosemary if it has taken frost damage.
How to Save Frost Damaged Rosemary
Rosemary is unlikely to be damaged by frost since only the roots cannot withstand it and the soil around them usually protects them from freezing.
It can still happen, however, and if it does, your best bet is to transplant your rosemary into the ground as it will have more soil around its roots to keep them warm. If you do this, it is important that you do it at the right time and find the right place for it. Of course, this only works for potted rosemary, but potted rosemary is also much more likely to take frost damage than rosemary growing in the ground.
You can also take cuttings from your plant and grow them as new plants to make sure you can keep growing rosemary, but then you might as well go out and get a new plant to get a headstart, in my opinion.