Overwatering is perhaps the most common problem people face when growing rosemary. Luckily, it is pretty easy to tell if a rosemary plant has been overwatered, and it is usually also pretty easy to save it.
In this post, I describe the five easiest signs to look out for to know if a rosemary plant has been overwatered and explain precisely how you can save it and prevent it from happening in the future.
The first signs of rosemary being overwatered are that the needle-shaped leaves turn yellow and brown, the plant begins to wilt (or droop), and some leaves may fall off. Additionally, the plant will slow or stop growing entirely, the soil won’t dry out, and powdery mildew may appear on the leaves.
If you suspect that your rosemary plant has been overwatered, but you are not sure, I recommend reading the rest of this post as I describe all the signs to look out for in greater detail and then share tips on how to save overwatered rosemary and how to prevent it from happening in the future. It is not complicated and can save you a lot of time and headaches in the future. I cover everything you should know below.
5 Signs of Overwatering Rosemary
It is not always easy to tell if a rosemary plant has been overwatered, and some of the signs can easily be mistaken for other issues, so I have written this post where I share five signs of overwatering to help you determine if that is the issue.
A while ago, one of my rosemary plants wasn’t looking fresh and healthy anymore, and it wasn’t until I reached out to a nearby plant nursery to ask for advice, I realized overwatering was the issue.
The person I spoke to at the plant nursery told me precisely what signs to look out for, how to save my plant, and how to prevent overwatering in the future, and I have never had the issue since then. I share everything I learned in this post.
Here are the five signs of overwatering rosemary you should look out for.
Sign # 1 – Leaves begin to turn yellow and brown
The earliest sign of overwatering rosemary is that the tip of the needle-shaped leaves begins to turn yellow. The change of color spreads pretty quickly to the rest of the leaf and then to other leaves.
After some time, the leaves begin to turn brown, and at this point, they are no longer able to obtain sunlight. When too many leaves turn brown, the plant cannot absorb enough sunlight to get rid of the water fast enough, which only causes the overwatering problem to become worse if you don’t do anything about it. I explain what to do about it later in this post after the five tips.
It is important to know that rosemary leaves can turn yellow and brown for other reasons than overwatering, such as excess nitrogen in the soil, overfertilizing, or underwatering, so keep reading to see the other signs.
Sign # 2 – Plant begins to wilt and leaves fall off
Wilting, or drooping, is when the non-woody parts of a plant begin to become soft, and the leaves fold and hang loose.
Rosemary can wilt for a couple of reasons, but one of the common reasons is too much moisture around the roots, which is a result of overwatering.
Like above, wilting can happen for other reasons than overwatering and is actually also a way for the plant to reduce the amount of sun it takes in, as the surface area of the leaves is reduced when they fold.
Sign # 3 – Soil does not dry out
An easy way to tell if your rosemary might be overwatered is to keep an eye on the soil and see if it dries out after watering.
The top 1-2 inches (2.5-5 cm) of the soil should become dry within a week of watering, and if it doesn’t, there is a chance the plant has been getting too much water, and the roots are unable to obtain it all.
Before I wrote this post, I talked to a gardener at a nearby plant nursery to ask for advice, but I also wanted to see what other people wrote online, and I kept finding the tip that you should look out for root rot.
The thing about root rot is that it happens underground to the roots, so you can’t see it unless you either lift the plant out of its container or dig it out of the ground. I don’t recommend doing this, and the gardener I spoke to agreed, as it can cause unnecessary stress to the plant, which can lead to other issues.
You should also know that just because the soil doesn’t dry out fast enough, it doesn’t necessarily mean that there is a big issue, but it is likely because the plant has been getting at least a little bit too much water for some time.
Sign # 4 – The plant stops growing
After a while of being overwatered, rosemary plants will begin to grow slower and slower and eventually stop growing at all.
This happens after a plant has been overwatered for a while and is a very clear sign that something is wrong, and it is usually because of overwatering, but it can also be because of lack of sunlight or other conditions not being met (more on that here).
You should also remember that even though rosemary is an evergreen plant, it will usually grow significantly slower or stop altogether during the winter.
Sign # 5 – Powdery Mildew on the leaves
Powdery mildew is a fungus that thrives in moist conditions. It is pretty easy to identify it as it looks like a white, powdery substance on your plant’s leaves.
Powdery mildew is not a direct result of overwatering and doesn’t always appear, but since the fungus thrives in moist conditions, overwatering plants increases the risk.
If you see all, or just some, of the signs I have listed here on your rosemary plant, there is a good chance it has been overwatered, at least to some degree. Luckily, you can often save overwatered rosemary if you know what to do. Below I share five tips that have worked for me to save overwatered rosemary.
How to Save Overwatered Rosemary (5 Tips That Work)
I love growing rosemary and not just for the tasty leaves but also because it is such a hardy and robust plant that can survive for up to about 20 years if they have the right conditions (more on that here).
One of the great things about rosemary being such a strong plant is that it can often be saved when you overwater it.
I have written another post where I go into much more detail with how to save overwatered rosemary, which you can read here, but if you just want a quick summary, stay here.
Here are five tips to save overwatered rosemary.
Tip # 1 – Remove yellow and brown leaves
For the plant to be able to focus entirely on growing and producing healthy new shoots, you should remove all the unhealthy leaves.
Look for yellow and brown leaves and remove them. Keep an eye on the rosemary plant and remove yellow or brown leaves as soon as they appear.
Tip # 2 – Let the top of the soil dry out
I have seen many places recommend that you water your rosemary plant on a fixed schedule and stick to it. I do not recommend doing this as everyone has different conditions, but instead, wait for the plant to show that it needs more water.
The best way to tell if a rosemary plant needs more water is to wait for the top 1-2 inches (2.5-5 cm) of the soil to become dry. When the top of the soil is dry, water the plant by following the next tip.
Tip # 3 – Water only the roots and not the plant
If you get water on the rosemary plant’s leaves, it can affect how well they can absorb sunlight and, thereby, how well the plant obtains and uses the water around its roots. Therefore, it is best to only water the roots and not the actual plant.
The best way to water rosemary is to only water the soil and roots and not the plant. For rosemary growing in the ground, simply pour water on the ground under the plant. For potted rosemary, it is best to water from the bottom by adding the water to the plate underneath the pot.
Tip # 4 – Move the plant to sandy soil
This is one of the most common causes of rosemary being overwatered.
The soil rosemary is growing in has a huge effect on how well the plant will grow since rosemary requires soil with good drainage to thrive. So if your rosemary is suffering from being overwatered, it can be a good idea to move it to a place with sandy soil.
The best soil for rosemary is loam, which is a type of soil that consists of sand, silt, and a smaller amount of clay. Soil for rosemary should ideally consist of about 40% sand.
I learned this from a paper about a study that investigated how different soil types affect how well rosemary grows, and as mentioned above, 100% loam worked best according to the study. You can read the study on this link.
Moving the plant to different soil is, of course, much easier with potted rosemary than rosemary that grows in the ground, but overwatering is also much more likely to happen to potted rosemary. Being able to move the plant easily is one of a few benefits of growing rosemary in a pot, but there are also some disadvantages (more on that here).
Tip # 5 – Move the plant to a sunnier place
Rosemary needs sunlight before it can obtain and use water to grow, so if there is not enough sunlight, the plant can’t obtain the water efficiently enough, and it will end up becoming overwatered.
One of the most common issues that lead to overwatering for rosemary is lack of sunlight. Rosemary needs a lot of sunlight and, in fact, can’t get too much sunlight in the vast majority of the world (more on that here), so the more, the better.
If your rosemary is suffering from overwatering, it is a good idea to identify a place for it where it can get more sunlight, as it will help it absorb and use the water in the soil around it more efficiently.
It is, of course, always better to avoid overwatering than to have to save the plant once it has happened, so I will share a few tips I have learned about how to prevent overwatering of rosemary below.
6 Tips to prevent overwatering Rosemary
I recently talked to a very helpful and super experienced gardener at a nearby plant nursery because I needed some tips to find the best place to plant rosemary, but part of what she told me was about how to avoid overwatering before it happens, so here are six tips to prevent overwatering rosemary.
Tip # 1 – Water when the top of the soil is dry
Water your rosemary when the top of the soil feels dry. Everyone has different growing conditions, so do not try to follow a fixed schedule, but instead, wait for the plant to signal that it needs water.
Tip # 2 – Use terra cotta pots for potted rosemary
Use terra cotta pots for potted rosemary to reduce the risk of overwatering, as they provide good drainage and allow the soil to “breathe”.
Tip # 3 – Water only the roots and not the plant
For potted rosemary, pour water into the plate underneath the pot. For rosemary growing in the ground, just keep the watering can close to the ground to avoid getting water on the plant’s leaves.
If you get water on the rosemary plant’s leaves, it can affect how well they can absorb sunlight and, thereby, how well the plant obtains and uses the water around its roots
Tip # 4 – Give rosemary at least 6 hours of sun per day
Plant your rosemary in a spot where it can get as much sun as possible. I have written this guide on how to find the best place to plant rosemary.
Rosemary essentially can’t get too much sunlight unless you live in the sunniest part of the world. The more sunlight it gets, the better it is at absorbing and using water. If it doesn’t have enough sunlight, it might not be able to obtain the water efficiently enough and it can lead to root rot which is a result of overwatering.
Rosemary should get at least 6-8 hours of sunlight per day, but the more, the better.
Tip # 5 – Grow your rosemary in sandy soil
Grow your rosemary in sandy soil as it has better drainage than other types of soil. This is one of the best ways to prevent overwatering. Do not use pure potting soil or garden soil, but instead mix about 40% sand in it to create a good mix for rosemary.
Tip # 6 – Give rosemary 2-3 feet (60-90 cm) of space
Give your plant at least 2-3 feet (60-90 cm) of space on all sides if it is in the ground and use pots no less than 12 inches (30 cm) in diameter and height for potted rosemary. This way the plant has enough room to develop a big and complex root system, which makes it much more resistant to being overwatered.