Peony Leaves Curling: Why And What To Do?

The number of ornamental plants has long been inexhaustible, and among them, the place of honor belongs to peonies. But to behold the beauty of peonies we must always be on the lookout for something bad to happen to our plants.

Cold weather, underwatering, disease, and sucking insects are the main causes of peony leaves curling. To fix curled leaves, water the peony when the soil is 2 inches dry and make sure it is in a place protected from cold winds. Provide the plant with good air movement and spray it with horticultural oil.

There are several other causes of leaf curl, such as pests or too much sunlight. In all of these cases, the peony may respond with curling and other symptoms. All possible cases of peony leaf curl can be found here in this article.

Temperature fluctuations

Peonies can grow almost all over the United States. They are actually very hardy plants and can withstand very low temperatures when in hibernation.

When spring arrives the plants awaken and unfurl their leaves. This is when the young leaves are most susceptible to temperature stress, and I’m not talking about frostbite now, we’ll talk about that later. Now I’m talking about the fact that in spring it often happens that it’s hot during the day and can be quite cold at night. This is the reason for the curling of the peony leaves. This is a defensive reaction of the plant and it tries to protect the foliage from damage.

If this is your case, you need to create a more comfortable environment for the peony. First of all, give the plant water, even if it has already taken root, still water it so that the soil is slightly moist, but do not overwater it.

The second is to give the plant some liquid fertilizer with a low concentration. This will provide a bit of energy for recovery. But do not overdo it, one fertilizer is enough.

Thirdly, shade the peony for a week or two, at least partially. I mean protect it from the harsh afternoon sun, but the plant can get some sun hours in the morning. When you notice that the leaves are no longer curling, then you can take the shade off.

Read also: Best Indoor Hydroponic System For Vegetables

Peony leaves curling and turning black or brown

Peony Leaf Blotch is often the cause of peony leaf curl. This disease is caused by the pathogen Graphiopsis chlorocephala (Cladosporium paeoniae). It is quite a serious disease and quite difficult to treat.

Symptoms include curling of leaves from edge to center and black or brown-red spots. The outer leaves are most severely affected. The spots can be as small as a quarter or even half of the leaf. A reddish-brown, dry leaf edge is also a distinctive feature of the disease.

The way to combat this disease is primarily through preventive measures. You should choose peony varieties that are resistant to spores of this fungus. Second, you need to plant peony at a sufficient distance from other plants to have good air circulation around it. Also, you should not over or underwater your peony. Do not leave any decaying plant debris around the bush.

If the disease does happen, you should spray the peony with an aqueous fungicide. You can find products in garden stores that can control the disease. Banner MAXX, Terraguard SC, or Broadform are good against this disease.

Pest damage

The first pest that causes peony leaves to curl is aphids. This pest creates colonies on the back of peony leaves and starts sucking the sap, causing the leaves to deform. Look at the underside of the leaf for small green insects. If there are aphids, you can wash them off with water or use Neem Oil to get rid of them.

The second pest is the spider mite. If you see fine cobwebs on peony leaves and they curl up, it could be a mite. Look closely for microscopic reddish bugs. If this pest is present, you need to use a special product called acaricide. It will take several sprays to get rid of this pest.

Next are thrips, which are also small bugs that suck the sap from the plant. Leaves can then curl and shrivel. They can be controlled with horticultural oil or insecticides.

And the end goes to scale. This pest is easy to spot by its white protective covering. It succumbs to the plant and feeds on it. If this pest has not yet multiplied on your peony, you can remove it with your hands. If it spreads too much, you need to spray the peony regularly with pesticides and horticultural oil.

Not enough water

Peonies cannot be called drought-tolerant plants, but they can survive a brief lack of water. But if the drought lasts for a long time, peony leaves will curl and then burn around the edge.

Such a feature is since this plant has a shallow root system and drying of the top layer of soil can hurt its appearance.

To avoid this situation, you should water the peony regularly. The best way to find out if it needs watering is to check the moisture in the soil. It doesn’t matter whether you do it with your finger or a moisture meter. If the soil is more than an inch dry, you need to water the plants.

The amount of water should be enough to moisten all the soil around it. Don’t water too much because the excess water will seep deep into the soil and the peony roots won’t be able to reach it. It is better to water 1-2 times a week with a shallow watering.

Too much sun

The sun can also cause peony leaves to curl. If there is too much light, the plant will try to protect the foliage by reducing its area (curling).

Not all peonies experience sunlight in the same way. Some varieties are more sun tolerant but some need less sun than others. Tree peonies are the most sun-tolerant, but they can also tolerate partial shade.

The best way to avoid curling leaves from excessive sunlight is to ask the seller about the sun tolerance of a particular variety. If a peony is already growing in your yard and has leaf problems, you need to transplant it to a place with at least 6 hours of early sun and afternoon shade.

Late frost damage

As I mentioned earlier, peonies are very hardy plants and are not afraid of frost. This is true for both herbaceous peonies and tree peonies.

But in spring the foliage of peonies opens quite early, this is especially true for tree peonies. As a result, late frosts can damage the leaves. If this happens, the leaves will curl and bend. The color may also change, if the damage is not severe the color will change to reddish-green. But sometimes the damage can be critical and the leaves can even turn black.

To avoid this scenario, you have to watch the weather forecast all the time in the spring. If it gets cold, you need to cover your peonies. You can do this with garden fabric, which is available at every horticultural store. Once the threat of frostbite is gone, the fabric should be removed.

Overwatering

Too much water leads to various symptoms, among which is also the curling of the leaves. In this case, yellowing or wilting of the peony leaves are also possible. Peonies like moist soil, but too much watering over a long period of time will harm their health.

It follows that peonies should be watered in moderate amounts. The soil around the plants should not be dry. Also, it should not be wet, but only slightly moist. One or two waterings a week during a drought is usually enough for the plant to thrive. Never water peonies in rainy weather. Even if it has rained lightly, still, don’t water.

Another problem is mulching peonies. Mulch is good in many ways, but too thick a layer of mulch will prevent air from getting to the ground and water will be retained for too long after heavy rains. Therefore, the layer of mulch around the peonies should be no thicker than 1-1.5 inches. There should also be a gap of at least 1 inch between the mulch and the peony stems.

Curling after moving

It is widely known that after planting from pot to soil or transplanting, plants go through a transplant shock. This is also true of peonies and one of the symptoms of transplant shock is the curling of the leaves.

The first thing to do is choose the right time to transplant, in this case, early spring or early fall. Also, the day should not be very sunny. Morning or evening is the ideal time of day to move the peonies.

Don’t bury the rhizome of the peony too deep into the ground. If you transplanted the peony at a time when the leaves have already unfolded, shade it for a few weeks with garden netting. Also, water it sparingly but often enough to keep the soil moist.

The peony will recover after a while, but you may not get any flowers this year. Also, the leaves can remain deformed until the autumn and only the following year will you get a fully healthy plant.

Roots

Root problems can also cause peony leaves to curl. This is primarily due to overwatering, if it rains a lot or if the peony is not watered properly, the roots can begin to rot. Root rot is actually a very serious disease, and you should treat it responsibly.

To avoid root rot, plant the peony in drained soil and water it in moderation as I said above. If the leaves continue to curl and turn yellow then you have to dig the peony out and check the roots for rot. If rot is present clean it off and washes the roots with water. Then spray the wounds with fungicide and sprinkle with crushed wood ash. Then plant the peony in a less damp place and shade it for a few weeks or even months.

The roots can also be damaged by certain insects or rodents. In this case, you also need to dig the plant up and treat the damage. Then plant the peony in a more protected location.

Nutrient deficiency

The peony is quite a large plant and it dies off every winter. In the spring it needs a lot of energy to regain its size. But when it is time to flower, it may not have enough energy to bloom and form seeds. As a result, the leaves may curl or droop.

To prevent this from happening to your peony, you need to feed it. I usually feed my peonies once a year in early spring. I use a slow-release fertilizer pelletizer as a feeder. As far as micronutrient ratios, equal parts Phosphorus, Nitrogen, and Potassium work well in my case.

I also sometimes practice liquid fertilization immediately after flowering. In doing so, I cut back the wilted flowers to keep the peony from losing its energy to make seeds. As a result, my peonies have been thriving and pleasing me with their fabulous flowers for many years.

Key Takeaways:

• A sudden cold snap can cause peony leaves to curl. Cover the peony for the duration of the cold snap.
• Diseases and pests often cause peonies to twist. Spray the leaves with horticultural oil or fungicide.
• Drought and too frequent watering can cause peony leaves to curl. Water peonies when the soil is at least 2 inches dry.
• Stress after transplanting and a damaged root system are often responsible for peony leaf deformation. When transplanting, be careful not to damage the roots and shade the plant for 10-20 days.