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Why Are My Magnolia Leaves Curling?

Magnolias have become widespread in horticulture because of their amazing flowers. However, with all trees, some trouble sometimes happens and magnolias are no exception.

Drought stress is a major cause of magnolia leaf curl. In addition, drastic fluctuations in temperature, pests, diseases, and herbicides can cause magnolia leaves to curl and deform.

All of these cases are described in detail in this article. You will also learn what to do to fix it.

Drought stress

magnolia tree leaves curling up

Drought stress

Because of the surface type of the root system, magnolia is very sensitive to soil moisture. If the soil is dry for a long time, it can cause drought stress.

As a result, the leaves curl inward to reduce moisture evaporation. In addition, the edge may become brown and dry.

This usually happens in hot summer weather and in the absence of rain for a long time. Rapidly draining sandy soils also exacerbate the problem.

How to fix it

The first thing to do is to water the magnolia well. Use at least one gallon of water per tree.

Next, monitor the moisture content of the soil in the root zone regularly. As soon as the soil is more than 2 dumas dry, water the magnolia. This should be followed for the first 1-3 years after planting the magnolia mainly during the summer months.

Also, mulch the root zone with organic mulch about 3 inches thick. Avoid putting mulch on the trunk of the tree. There should be a gap of at least 1 inch between them. For more information on magnolia’s water needs, please check out How often to water Magnolia.

Herbicide damage

new magnolia leaves curling

Herbicides

Herbicides are designed to kill weeds, but they can also kill a cultural plant. These chemicals are usually used to clear the lawn of weeds.

During treatment, the wind can blow some of the herbicide onto surrounding plants and trees. This means that even if you didn’t use the chemicals your neighbors may have done so and your tree is affected.

Depending on the amount and composition of the chemical, the damage will vary. One symptom may be curling leaves. If the chemical is strong, it may even burn the leaves.

How to fix it

To date, there are no effective methods of reversing the effects of herbicides. All you can do is wash the magnolia leaves to wash away any residue of the chemical if there is any left. After that, water the tree well.

Next, take proper care of your magnolia tree and it should recover. The curled leaves will never be the same again, but the new ones will be straight and beautiful.

Read more: Detailed Guide To Growing Healthy Magnolia Trees

Disease

magnolia leaves curling disease

Disease

Diseases are a common cause of deformed magnolia leaves. There is a variety of such diseases, but the most common are fungal diseases.

Here, powdery mildew is the most common. This disease affects the leaves and makes them twisted or wavy. There may also be a white powdery appearance on the leaf plate.

There are also some other pathogens that can cause leaf curl. In this case, brown spots usually appear on the leaves, or even entire parts of the leaf become discolored.

How to fix it

Make sure there is good air exchange around the magnolia. Do not plant other plants too close to it.

Make sure the magnolia gets at least six hours of direct sunlight a day.

The place where the magnolia grows should not be damp. Avoid overwatering it.

If the leaves show symptoms of disease, spray them with a multi-purpose fungicide two to three times at two-week intervals. Neem oil also does a good job on powdery mildew.

Insects

magnolia leaves curling down

Insects

Sucking insects always cause leaf changes. This applies to almost all plants, including magnolia.

Aphids are probably the most common pest of this type. They usually parasitize young and soft leaves.

From the underside of the leaf, the aphid penetrates the tissue and feeds on the sap of the plant. As a result, the leaf curls downward and creates a dome under which the pests multiply.

The second sucking insect is the scale. These pests also feed on the sap of leaves or young branches. They can be seen as white flakes. If they have settled under a leaf, it will certainly become deformed. 

How to fix it

If you find insects on twisted leaves, spray them with an aqueous solution of horticultural oil. Repeat the spraying after a week.

The hardest thing to do is to get rid of the scale. Therefore, a systemic insecticide should be used against this pest. For more information on magnolia tree pests, see – What Bugs Eat Magnolia Trees?

Temperature stress

magnolia leaves curling

Temperature stress

The next factor that affects the shape of the leaves is the weather. If your area has drastic changes in temperature this can have a negative effect on the tree.

Also, too hot weather can cause a magnolia to ‘clump’ its leaves to reduce overheating. Because magnolia leaves are large, they heat up quickly and, to avoid damage, the tree reduces their area by folding them in half.

The leaves may also develop a reddish-brown tinge. This is a pigment that helps to reflect the sun’s rays, resulting in less heat on the leaves.

How to fix it

There is nothing to be done about this problem because it is a natural process. Usually, only young or potted trees suffer from temperature stress.

But if you want to improve the situation of your magnolia, you can shade it for the duration of the heat if the size allows. Also, mulch the root zone to keep the roots cool. One extra watering will also do some good.

New Magnolia leaves curling

Newly planted magnolias most often suffer from leaf curl. This is due to the fact that they have not yet developed a root system as well as the crown.

New magnolias are very dependent on the amount of water they receive because the roots cannot yet supply enough water from the soil. They are also not able to regulate the internal temperature properly, so they can easily suffer from temperature stress.

How to fix it

The first thing to do is to shade the newly planted magnolia for the summer heat. To do this, use shade netting or an umbrella.

Check the soil frequently for the first 2-3 years. If it is more than 1-2 inches dry, water the magnolia with at least 1 gallon of water.

When planting, avoid injuring the roots. Plant and transplant magnolia only in early spring.

Mulch the tree with 2 inches of organic material. Avoid volcano mulching.