Why do Rosemary Leaves Curl? Causes and Solutions

Rosemary is an evergreen tender herb native to Asia and the Mediterranean growing in sunny and warm climates. But sometimes you would notice the tips of Rosemary leaves curling.

Leaves of Rosemary can curl due to low humidity, over-watering, lack of sunlight, soil issues, over-fertilization, pest attacks, etc.

9 Reasons for curling rosemary leaves and how you can fix them

Let us look at each of the reasons in detail

1. Low humidity

This perhaps is often the reason why you will find the Rosemary leaves drooping. The lack of moisture in the atmosphere causes the Rosemary leaves to dry and curl.

You would think to water the Rosemary plant but that can be disastrous. Instead, you need to provide a bit more humid and slightly warm climate around your Rosemary.

Solution

As Rosemary takes more water from the air than from the roots, find a location where there is higher humidity and plant it there.

You can also place the Rosemary pot above a plate filled with stones. Put some water on this plate.

We would recommend only half of this to be filled with water as this will allow enough water evaporation for the leaves of Rosemary.

You can also use a sprayer to provide moisture to the leaves. Regulate the nozzle for a mist spray rather than a jet spray

2. Over Watering

Before growing any plant in your garden, it is necessary that you do a bit of homework. This is just to get in-depth knowledge about the nature of the plant you choose to grow.

The leaves of the Rosemary plant can wilt and turn brown due to Over watering as well. You might think this is the cause of the lack of water. But it is more likely a cause of over-watering.

Too much water in the roots can cause the plant to suffocate and the curling leaves can be a sign that your Rosemary is dying due to a lack of nutrients available to it.

Rosemary is a water-sensitive herb. The fact about rosemary is that it takes water more from the air than from the soil. Originating from the Mediterranean, it prefers dry soil.

Solution

Rosemary plants can be saved from over-watering if some of the roots are still out of damage and alive.

You need to first pull out the plant and check the roots. If you see some roots are alive you are lucky and you can save the plant.

You would need to slow down on watering and change the soil to a fast-draining one.

If you are growing rosemary in the pot, then keep enough holes in the pot. This will enable the excess water to run out. Make sure to shift the rosemary plants under any shade during monsoons.

If you are growing rosemary in the ground, then change the location with proper care without damaging the live roots.  Make sure to grow rosemary in such a place in the ground where the effect of rains is less.

Many gardeners leave rosemary grown outdoors without water for many days. They do this so as not to suffocate the roots.

3. Lack of Sunlight

As we already know, rosemary is native to Asia and the Mediterranean regions. They are known to grow at their best in sunny and warm conditions.

Rosemary plants need plenty of Sun, nearly 6 hours, half of the day as they are heat-tolerant plants and it is really difficult for them to survive in weak sunlight.

Rosemary will start curling and drying without adequate sunlight. It is very imperative to correct the unfavorable conditions to save the rosemary from dying.

Solution

Provide 6-7 hours of sunlight daily to your rosemary. Re-locate them to a sunny area if you have planted them in a shade.

Growing rosemary in pots is more advantageous because of the mobility. If you are growing them outdoors, grow them in such an area where they are not that affected by rains.

If you are growing rosemary indoors, you can use garden glow lights or Grow LED lights for 10-12 hours a day for better results.

4. Soil Issue

No doubt rosemary is a delicate plant considering its soil needs but it does not mean it is difficult to give it a suitable soil mix.

Rosemary requires fast-draining alkaline soil. It will die in clay soils particularly in the winter season when the ground tends to be wetter.

Solution

A well potting mixture or soil made up of sand, loam, and clay with essential nutrients will make your rosemary grow faster than expected. The preferred soil pH for Rosemary is between 6.0 and 7.0.

The typical soil for rosemary would be two-thirds of regular potting soil with one-third of perlite. Gardeners prefer mixing perlite instead of the regular potting soil because of its capacity to flush excess water.

Adopting the perlite mixture has negativity too. This mix sometimes fails to maintain the proper drainage. You can overcome this by either adding more perlite or lessening the frequency of watering your rosemary.

There is one more alternative. Mix 30% horticultural soil with 70% compost. This mixture helps in reducing the rotting of roots.

5. Over Fertilization

Rosemary is a plant with fewer requirements. It adapts itself to medium nutrient soil too.

Too many fertilizers will burn the roots. Particularly, if you use fertilizers with high nitrogen content, this is bound to happen.

The symptoms of rosemary wilting due to high nitrogen are:

  • Drooping of both leaves and stems.
  • Leaves turning yellow or brown.
  • Soft dense foliage

Solution

You should slow down on the application of fertilizer. There is no general rule for fertilizing rosemary plants. It largely depends on the type of soil you use, the age of the plant, etc.

You can use a bit of dry fertilizer or liquid soluble fertilizer. Apply only once in early spring for good results and better growth.

Make sure your fertilizer is non-toxic so that the nutrients are absorbed by the plant gradually without any damage.

If rosemary is grown at home, then it is always advisable to go for possible organic ways. Commercial fertilizers can affect the taste and aroma.

Good Rosemary Companion plants and what not to plant with it

6. Pest Attacks

Common pests that affect rosemary are aphids, spittlebug, thrips, spider mites, etc.

The leaves of rosemary tend to curl when these pests attack them. These pests are very tiny and they often go unnoticed even before they start severely infesting the plant.

Aphids

Aphids suck the nutrients from the rosemary and make them weak.

How to control aphids on Rosemary?

A lot of natural methodologies can be adopted to get rid of aphids. To name a few,

  • Pick them off
  • Remove diseased plants
  • Give a hard blast of water
  • Spray essential oil mixture
  • Create bird habitat

Spittlebug

Spittlebugs affect rosemary by leaving saliva like foam. These pests feed on the sap of the roots.

How to control Spittlebugs?

  • Crush the larvae
  • Spray organic pesticides

Thrips

Thrips attack leaves, leaf buds, etc. Severe infestation can destroy terminal buds. This will result in delayed plant growth.

How to control Thrips on Rosemary?

Try using insecticidal soaps which contain fatty acids. These soaps paralyze these pests and kill them.

Always try to use natural home remedies that won’t harm your plants.

How to remove spider mites on rosemary? Check out

7. Rosemary Transplant Shock

Another reason your rosemary may curl is transplant shock.

This is caused by the contradictory conditions between the garden from where you bought your rosemary plant and your garden.

The reasons for this contrast may be humidity, watering frequency, heat, sunlight, soil mixture, change in environment, and other factors. This is an indication of stress that is making your rosemary curl.

Solution

The right way to handle your wilting rosemary suffering from transplant shock is to support your plant with ideal growing requirements.

In simple words, you should match your rosemary’s growing conditions to Mediterranean regions, which is its native habitat.

8. Viral infection

Botrytis blight is a viral infection. In this infection, the leaves start curling and decaying around the middle part.

This occurs in high humidity conditions, chill weather, and lack of aeration. If left untreated, it can very rapidly spread to the rest of the healthy parts of the plant.

You should give sufficient space between your plant pots and keep rubbish away if any.

9. Extreme Winter

Rosemary is not cold-resistant and it can only withstand mild winter. Frost and snow will curl the leaves.

The remedy to this depends on the area where you grow. If your area has more chill conditions, then you should grow your rosemary in containers or pots that you can shift indoors or to a warmer area during extreme winters.

Planting rosemary in a larger pot also will help. The soil will generate heat and keep the roots warm.

What if your rosemary is outdoors and it is winter?

Cover them with woolen clothes or fur. It will avoid cold damage to some extent.  Low humidity always promotes leaf curling. You should also avoid pruning during winters.

Conclusion

To summarize, you should Keep water and fertilizer levels at a minimum, give your Rosemary the warmth of the bright sun, and check frequently for pests and diseases for preventing the curling of Rosemary leaves.