It is far from uncommon that some of the foliage on a rosemary bush begins to turn yellow or brown and eventually die off. It can happen for many reasons and while it usually isn’t critical, you should remove the dead growth when you see it.
The easiest way to remove dead foliage from a rosemary bush is to cut it off with clean and sharp pruning shears. It is usually best to cut about half an inch (or about 1 cm) below the dead part of the foliage although there are exceptions where the whole stem should be removed.
I have been in this situation many times so I wrote this article because I figured I probably wasn’t the only one. In the article, I explain precisely what you should do if you find yourself in a situation where some of the growth on your rosemary suddenly seems to be dying.
Since I wanted to share as much helpful information as possible, I also reached out to an expert gardener I know from a nearby garden center who is always ready with some tips. He shared some excellent information about why some of the foliage on a rosemary bush sometimes dies, why it is important to remove it, and how to reduce the risk of it happening. I share everything I learned in this article.
How to Remove Dead Growth From Rosemary (I Asked an Expert)
It might be a bit unnerving if some of the foliage on your rosemary suddenly begins turning yellow or brown and dry, but you don’t have to worry. At least not yet. I have been in that situation many times over the years and it is usually not a big problem.
Before I wrote this article, I had a good talk with Arne, a very knowledgeable gardener with several decades of experience from a nearby garden center. Arne agreed with me and said that while it usually isn’t a big problem, you still have to do something about it.
If some of the foliage is starting to become yellow or brown and dry, you have to remove it. How you should do it depends on the specific situation, though.
More specifically, it depends if only the tips of some of the stems are dying (like my plant in the photo above) or if the entire stems are affected.
If only the tips of some of the stems are dying, remove them by cutting about half an inch to one inch (or about 1-2.5 cm) below the affected foliage. Make sure you cut into the fresh and healthy part of the stem to remove all the affected foliage.
If entire stems seem to be affected and dying, make sure to remove them entirely by cutting them at the base.
Pruning shears are usually sufficient but you might need stronger tools for thick and woody branches. I wrote another article where I go into detail about the tools needed for pruning rosemary, which I recommend reading so you can determine what you need for your situation.
Depending on what time of the year you are experiencing this, it might be beneficial to give your rosemary a proper pruning. Be careful with that if it is cold outside, though. I explain why you probably shouldn’t prune your rosemary in cold months here.
Even though it is usually not a big problem, you should still make sure to remove any dead growth from your rosemary when you notice it. I will explain why now.
Why You Should Always Remove Dead Growth From Rosemary
It is important that you remove all the affected foliage but try not to remove too much of the fresh foliage. By cutting into the fresh and healthy part of the stem, you can actually make your plant nicer and more productive over time.
That’s not the only reason why you should do it, though. Let me elaborate.
Cutting fresh rosemary stems will cause them to split into two or more, causing the plant to become bushier and more productive overall. This is an excellent way to turn a leggy and scraggly rosemary bush into a nice, bushy, and productive plant.
I’ve been surprised by how effective this can actually be and it was also one of the benefits Arne, the expert gardener I spoke to before writing this post, put the most emphasis on.
It wasn’t the only benefit of removing dead growth from rosemary we talked about, though.
- Removing dead growth from your rosemary is important since it can be infected and spread to other parts of the plant if it is not removed. This isn’t always the case but it is better to be safe than sorry.
- Removing dead foliage will free up space for the fresh and healthy foliage to grow.
- Removing dead growth can help improve airflow and thereby reduce the risk of several problems such as mold or mildew.
- Removing dead or dying foliage allows the plant to funnel its energy into the fresh and healthy foliage rather than spending it on trying to keep the dying foliage alive.
- Pruning away dead foliage promotes growth and causes the plant to become bushier and more productive.
Lastly, Arne, the expert I talked to, mentioned that while it might not be the primary benefit, removing dead foliage also makes the plant more aesthetically pleasing to look at since only the green and healthy foliage is left.
If you want to learn more about this, I have another article where I cover the importance of pruning your rosemary, whether removing dead growth or trimming the healthy growth.
Removing dead growth is important but it is only one part of the pruning process. If you are planning on going through that process, I recommend reading my full guide on how to prune rosemary to get the best results.
Why Some of Your Rosemary Is Suddenly Dead (Expert Explains)
It is very common to see some dead or dying foliage on rosemary plants. In fact, it is strange if it doesn’t happen since it is a very natural occurrence.
Of course, rosemary can become damaged by a bunch of different pests and diseases but more often than that, it is caused by something much more harmless.
According to the expert gardener I spoke to before writing this article, the most common reason for rosemary foliage dying is that it happens as a result of a minor fungal infection or similar caused by humidity.
Because of that, it is especially common to see it in the fall or winter but it can happen throughout the whole year.
Dead growth is one of the most common signs that you should consider pruning your rosemary. If you want to learn what else to look for, I recommend reading one of my other articles where I cover several signs that you should prune your rosemary.
Rosemary doesn’t like frost much so when the end of the year is getting close, you will often see some of the foliage turning brown or drying out. There is actually something you can do about it, though. The expert gardener I spoke to shared a good tip for that, which I cover below.
How to Prevent Rosemary Foliage From Dying: Tips From Expert
While it can’t be prevented entirely, you can reduce the risk that some of the stems and leaves on your rosemary die. Arne, the expert I talked to about this shared a great trick.
Cover your rosemary and the soil around it with spruce branches or a plant cover in the winter to reduce the risk of frost damage. Make sure to use a material that allows air to flow since stale air can lead to damage. That’s why spruce branches work well but a denser material such as plastic won’t.
If you happen to have a bunch of spruce branches, use those, but otherwise plant covers are usually inexpensive and can work very well.