Rosemary leaves tips can often get curly inwards, mainly when grown indoor. This is not generally a good sign, and you might need to take action. However, the good news is that the solution can sometimes be quite easy and take just a few minutes.
Curly rosemary leaves are the result of an insufficient level of humidity. This causes the leaves to dry from the tips and to curl down. This symptom can be addressed by increasing humidity levels of the air around the plant through adequate watering.
Hence, why the rosemary curl, and what to do in such a case.
Rosemary is an herb native of rocky areas close to the sea (check more on rosemary facts). This is the real secret to understand how to grow successfully rosemary as well as any other herb.
You need to replicate those native conditions if you want your herbs to thrive.
In particular, it is very well known that those areas close to the sea have significantly higher humidity than inland and, ever higher of what you might have at home.
To give you a perspective, scientists test how well rosemary (and other herbs) grow by setting a humidity a “normal” humidity level of 80%. The normal humidity level in your house is generally between 40 and 60%. These are the ideal values you should have, according to the American Society of Heating and Air Conditioning Engineers. Hence, there is a significant gap between what your home can provide and what your rosemary needs.
Of course, that does not mean that you need to provide precisely a humidity level of 80%. That is a lab test. However, you should be on the very high end (60% or above) to allow the plant to thrive.
To recover rosemary with dry leaves, you need to provide that extra moisture that is missing in the location where you placed it. Here three ways (you can apply all of them at the same time if you can to increase your chance of success)
Your house is quite a big place, especially for something as little as a rosemary plant (if it did not get gigantic yet). Hence, it should not be a surprise to you that the humidity level within your house can change significantly (even within the same room!).
Remember, humidity is just water in the air. Hence, whenever water usage increases, the moisture level is expected to be higher as some water will naturally evaporate. Moreover, warm air can hold way more humidity than cold air.
Hence, when looking for a place where to place potted rosemary, look for corners tht are naturally slightly warmer (no radiator, that is way too hot) and humid. Avoid dump places, as this can cause fungi on the plant. In general, a kitchen is a great place for the presence of a tap. The bathroom is not bad, either. However, I do not recommend it due to the lack of air movement (especially if you are unlucky enough that you do not have windows and only rely on a fan).
Indeed, after humidity, another factor that can make the situation worst is the lack of air movement.
This is another technique that I use to revive a few rosemary plants with curly leaves. What you need are a plant saucer and some rocks/pebbles. If you do not have a saucer, you can buy one here on Amazon.
Regarding the gravel (pebbles or similar material), anything is ok. If you take it from outdoors, be sure to boil or wash them with soap thoroughly. The last thing you want is to let unwanted (often small) bugs inside your house to attack and (potentially) weaken even more your rosemary.
Finally, place the rosemary planter on top of the saucer filled with rocks and place some water in the saucer to fill the space between the rocks (do not fill the saucer entirely, just ¾ of the saucer filled with water is fine).
This water, standing between the rocks, will slowly evaporate, creating extra moisture around the rosemary. From time to time, let the water dry out completely or give a quick rinse to the saucer. This avoid any problem with water-loving insects (that might access the outside when leaving the windows open.
Another alternative, despite requires a bit more effort, is to use a sprayer. A sprayer is indeed a quick way to provide some moisture to the leaves. However, it is not among my favorites because it requires at least 2-3 times a week’s applications. Moreover, using a sprayer indoor, especially if your herb is close to a window, can be a problem. You might end up spraying the window as well.
If you go for the sprayer, remember to regulate the nozzle to have more of a mist rather than a jet of water. It is generally not a good idea to water the leaves, especially if indoors with poor air ventilation (due to the possible formation of fungi).
Chatting with some friends on Facebook groups and offline, I noticed some common mistakes when trying to solve the curly leaves problem. Here a complication of the most common.
Curly rosemary leaves are getting dry. This is a fact. Hence, you might be tempted to water it more. This is the wrong approach that will lead your rosemary to sure death.
Indeed, those leaves absorb water from the air, not only from the roots. Also remember, that rosemary, is a dry-soil loving herb. It grows among rock cracks, where water flows pretty freely.
You know that rosemary grows in sunny places, close to the sea. Hence, why not place the planter on top of a heater radiator? This is another bad idea. Indeed, the heat, transmitted to the soil, is enough to kill the plant and cause curly leaves in the first place!
This is because the heated indoor winter air is typically very dry. Indeed, the indoor air is just outdoor air (dry due to the low temperature) that has been simply heated up once inside. It is this jet of scorching and dry air that can actually trigger curly leaves.
This has indeed happened with a few indoor gardeners I spoke with. That also explains why curly rosemary leaves are a more common problem in winter than in summer.
Dry-looking rosemary does not benefit from a filled saucer, on the opposite.
Previously I discussed the idea of creating a small humidifier with a rock-filled saucer and some water. However, I told you to avoid filling the saucer. This is extremely important! Forget this detail, and you can damage the rosemary.
Indeed, if you fill the saucer, the bottom of the planter and so the soil, will continuously be wet (as your rosemary planter has drainage holes, if not buy a new one). Chances are that even the bottom of the planter has some roots and, moreover, the soil act as a sponge, moving the water (a bit) upwards. This is a severe problem.
This, of course, applies even more if you do not have rocks in the saucer. If you want your plant to live longer, remember to empty it after each watering, especially if quite full.
Why? Remember what I told you before? Rosemary is an herb that thrives in rocky soil. This is the most drainage efficient medium. Rosemary is drought resistant and evolved to receive a lot of water once in a while when it rains and stays dry for a long period. Hence, if you keep its “feet constantly” wet, your rosemary will die of root rot. For this problem, there is almost nothing you can do (it can be saved, but it will be quite a substantial time investment).
Remember, rosemary is an herb that hardly ever needs fertilizer. Curly leaves and stunt growth are not generally connected, but they are related. Indeed, curly leaves, as discussed, happened more often in winter due to the drier indoor air.
The same applies to stunt growth. Indeed, during the winter, rosemary stays still, becoming more woodier rather than actively growing. This is normal. What rosemary potted plants need in winter is just humidity and very little water, definitely not fertilizer.
Curly leaves, due to their dryness, can also develop brown tips. In such a case, I will proceed by removing those leaves (no more than half of the total leaves). This is because those leaves are not producing much anyway, and are a burden for the plant. Hence, it is better to pinch them off to promote new growth (that will not happen during the cold season as the rosemary tends to slow down during winter).
Here a few important takeaways to remember.
- Rosemary curly leaves are quite often caused by a low humidity environment.
- Increasing the natural water content in the air is the best and long-lasting solution
- The rock-filled saucer is by far the best solution, if not a better location can be found.
- Avoid to water more the rosemary, this is easily turning into a problem rather than in a solution.
Can you overwater rosemary? It is very easy to overwater rosemary and cause several problems such as root-rot. Indeed, rosemary is an herb that thrives with seldom watering and extended periods of dry soil.
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