Given the right conditions, rosemary plants thrive, eventually reaching heights of 6 to 8 feet (2 m. ). They grow both up and out, sending out stems that seem determined to explore their surroundings and take over the space of plants next to them.
If your rosemary plant has grown out of control, its time to take drastic action. Rejuvenation pruning of rosemary may be needed.
Rosemary is a beautiful, aromatic herb that thrives in warm climates But even hardy rosemary plants can suffer damage when unexpected freezing weather hits If your rosemary bushes experienced frost burn or dieback from a hard freeze, you may wonder if they will recover and grow back in spring. The good news is that with proper care, rosemary can often regrow after being frozen.
How Cold Temperatures Damage Rosemary
Rosemary (Rosmarinus officinalis) is native to the Mediterranean region. It prefers hot dry conditions and temperatures between 55-70°F. When the mercury drops below 25°F for extended periods tender new growth on rosemary will blacken and die back. Prolonged freezes well below its tolerance zone of 10°F can kill the entire plant.
Freezing devastates the sensitive foliage and tender stems. It can also damage the root system if the ground freezes solid for too long. Bark split from expansion and contraction with temperature swings further stresses the plant. However, rosemary’s woody base and roots are quite hardy and often survive even when the top growth is destroyed.
Signs Your Rosemary Suffered Freeze Damage
How can you tell if your rosemary was impacted by winter’s cold? Look for these signs of freeze injury:
- Blackened, wilted shoots and leaves
- Drooping, dried out stems
- Split bark and cankers on stems
- Loss of foliage and dieback of branches
- Discolored, mushy areas on roots and root collar
The extent of the damage depends on how cold it got and how long sub-freezing temperatures lasted. Light frost may only burn tips while severe cold snaps can kill the entire plant above ground. But don’t give up hope yet!
Will My Rosemary Recover and Grow Back?
If freezing weather killed part or all of your rosemary plant above soil level, don’t assume it’s totally gone. Rosemary’s extensive root system is quite resilient and will often send up new growth when warmer weather returns. Here’s what you can expect:
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Mild freeze damage – Minor dieback of shoots and leaves. Plant will likely recover on its own by early summer. Just prune back damaged parts.
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Moderate freeze damage – Significant dieback but some stems remain intact. Can regrow from roots and remaining branches by mid summer with proper care.
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Severe freeze damage – All top growth killed. Roots may survive under ground and generate new shoots by late summer if adequately tended.
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Prolonged deep freeze – Entire plant including roots killed. Little chance of regrowth. Replace with a new plant.
So monitor your rosemary’s roots and lower trunk. If you scrape away bark and find green underneath, there’s a good chance of regrowth. Don’t prematurely pull it out!
Caring for Freeze-Damaged Rosemary Plants
Nurse your traumatized rosemary back to health with attentive care:
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Cut away all dead stems and leaves to prevent decay and disease.
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Shield roots from further freezing. Mulch around base for insulation.
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Water deeply every 2-3 weeks if winter is dry. Avoid excess moisture.
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Fertilize emerging shoots in spring with balanced 10-10-10 or nitrogen-only formulas.
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Stake and train any floppy new growth that appears.
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Transplant to container if root damage is severe.
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Be patient! It may take until late summer for significant regrowth.
With diligent care, many frozen rosemary plants will reward you with vigorous new branches and leaves as temperatures warm. But some may struggle to come back depending on how extensively they were damaged.
When to Replace a Frozen Rosemary Plant
If spring and summer pass without any signs of life from damaged rosemary, it’s time to replace it with a new plant:
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No new shoots or growth by early summer means roots likely died.
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Failure to regrow by late summer confirms the plant didn’t survive.
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Root or trunk rot indicates total loss. Dead plants invite disease.
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Woody base is brittle and breaks off easily when bent.
Depending on the variety, try replanting rosemary in fall or early winter before ground freezes again. Choose a protected area and mulch for extra insulation.
Preventing Freeze Damage to Rosemary
While we can’t control winter weather, properly preparing rosemary plants in fall will help them fare better when the mercury plunges:
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Select cold-hardy varieties like ‘Arp’, ‘Madeline Hill’, and ‘Benenden Blue’.
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Plant in well-draining soil against a heated south-facing wall for extra warmth.
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Avoid excessive late season fertilizing which creates tender growth.
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Prune plants in mid fall to reduce freezing risk to new shoots.
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Water thoroughly before ground freezes to keep roots hydrated.
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Mulch around base with evergreen boughs or other organic materials.
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Cover plants with fabric row cover overnight if hard freeze is forecast. Remove daily.
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Container-grown plants can be moved to unheated garage or basement temporarily.
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Delay planting new rosemary until spring to skip winter exposure.
Enjoying Rosemary Again After Winter Damage
Freezing weather can definitely take a toll on rosemary. But with proper follow-up care, most plants will regain their splendor eventually. Expect some setbacks, but don’t give up too fast. Just tend diligently and exercise patience. The amazing fragrance and flavor of homegrown rosemary are worth the extra efforts.
Frequency of Entities:
rosemary: 24
freeze: 16
plant: 10
roots: 7
damage: 6
grow: 5
leaves: 5
stems: 5
shoots: 4
cold: 3
foliage: 3
winter: 3
bark: 2
branches: 2
container: 1
disease: 1
Can You Hard Prune Rosemary?
Some gardeners are afraid to make big cuts on rosemary shrubs because some herbs with similar, woody stems don’t come back after big cuts. A mature rosemary plant, however, tolerates this drastic pruning, even into the woody parts of the stem.
Light pruning and harvesting can be done at any time of the year, but hard pruning works best on a rosemary plant when it’s not growing. When pruned in winter, the plant grows back in spring looking better than ever. Read on to find out how to rejuvenate a rosemary shrub.
Note: For most people who grow rosemary, the plant will go through a cold period. It’s not a good idea to prune any herb, including rosemary, right before or during cold weather because it will make the plant grow new shoots that are easily damaged by the cold.
In warmer places, rosemary is more likely to reach the size that needs to be pruned to make it look better. This is because the plant isn’t being killed by the cold, so pruning in the winter when it’s dormant is best. For those of us who don’t live in those places, though, don’t prune until after the threat of frost has passed.
The first thing you need to do to bring rosemary plants back to life is decide what size you want them to be. If you cut the bush back to about half of its full size, it will fill the space by the end of spring. You can maintain the size of the shrub through summer with light pruning and harvesting.
Why Is My ROSEMARY PLANT DRYING? (3 REASONS and How to AVOID IT)
Can Rosemary survive frost?
Rosemary can survive a fair amount of frost without taking any damage. That only goes for the plant itself, however, because if the roots freeze, the plant will die. I have found seven things you can do to help your rosemary survive the winter and come back stronger than ever in the spring.
Does Rosemary come back every year?
So rosemary technically doesn’t come back every year, but that is only because it never goes away. Rosemary is a perennial herb which means it can survive and grow for multiple years (more about that on this link ). The rosemary plant itself is frost resistant and can survive cold winters in most parts of the world.
Will Rosemary grow again in the spring?
As a general rule, rosemary will begin to grow again in the spring once the temperature starts to increase. Rosemary is a perennial herb, which means it can live for multiple years. The plant itself can even tolerate some frost, making it able to survive the winter in most parts of the world.
Will Rosemary come back in the winter?
The plant itself can even tolerate some frost, making it able to survive the winter in most parts of the world. Even though rosemary usually survives the winter and resumes growing in the spring, there is no guarantee. There are a couple of things you should know about to be sure if your rosemary will come back, which I cover in this article.
