Magnolias have become widespread in horticulture because of their amazing flowers. However, with all trees, some trouble sometimes happens, and magnolias are no exception.
QUICK ANSWER: 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.
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.
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, regularly monitor the moisture content of the soil in the root zone. When the soil is more than 2 inches dry, water the magnolia. This should be followed for the first 1-3 years after planting.
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.
Read also: How often to water Magnolia.
Herbicide damage
Herbicides are designed to kill weeds but can also kill a cultural plant. These chemicals are usually used to clear the lawn of weeds.
The damage will vary depending on the amount and composition of the chemical. 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 chemical residue if there is any left. After that, water the tree well.
Next, take proper care of your magnolia tree, which 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
Diseases are a common cause of deformed magnolia leaves. There are various such diseases, but the most common are fungal diseases.
Powdery mildew is the most common disease here. This disease affects the leaves, making them twisted or wavy. The leaf blade may also have a white powdery appearance.
Some other pathogens 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. Ensure the magnolia gets at least six hours of direct sunlight daily. The place where the magnolia grows should not be damp.
If the leaves show disease symptoms, spray them with a multi-purpose fungicide twice or thrice at two-week intervals. Neem oil also does a good job on powdery mildew.
Insects
Sucking insects always cause leaf changes. 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.
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.
Read also: What Bugs Eat Magnolia Trees?
Temperature stress
The next factor that affects the shape of the leaves is the weather. If your area has drastic temperature changes, this can hurt the tree.
Also, too hot weather can cause a magnolia to close its leaves to reduce overheating. Because magnolia leaves are large, they heat up quickly, and to avoid damage, the tree reduces its area by folding them in half.
How to fix it
Nothing is 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 because they have not yet developed a root system or crown.
New magnolias depend on the amount of water they receive because the roots cannot yet supply enough water from the soil. They can also not 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.
When planting, avoid injuring the roots. Plant and transplant magnolia only in early spring. Mulch the tree with 2 inches of organic material.
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I have planted a magnolia in a large pot earlier this year. It seems to be growing well but not looking very healthy – with leave curling and wilting, flower buds dying out without coming to bloom – see photos. Can you please recommend what needs to be done..
Hello,
I recommend transplanting your magnolia from the pot to somewhere in the yard next spring. Magnolia is a rather large tree and growing it in a pot is not a good idea. In a pot there will be a constant problem with root bound, overheating, lack of nutrients and water.
However, if you decide to keep it potted, place the tree so that the sun does not heat the pot. It is best to place the tree on the east side of the house so that it receives direct sun only in the morning.
Water when the soil is 2 inches dry and make sure the pot has drainage holes. Mulch the surface to prevent the soil from drying out quickly.
Apply a slow release fertilizer in the spring. In addition, water the magnolia several times during the year with a liquid fertilizer.
I hope my tips will help you. I look forward to hearing from you about your magnolia!
hello
i have two magnolia one in the front yard and one in the back….this is the second year the leaves have formed an curled downward….just like the photo with the herbicide damage….i do not use any herbicides….there is a field down from my home about 1/4 mile that will spray in the spring…there are homes in between and i have seen no damage to other trees….i also have other trees in my yard that show zero signs of damage….my neighbor has a company come and spray their yard for mosquitos….again between the tree and the yard no other damage….i am at my wits end trying to figure out the cause…is it the tree itself? the leaves are just coming on because its spring but again the curl is all over….some have told me its my soil…these trees are established and years old…not new plantings not a couple years….please help
Hi Tracy,
Check the leaves for pests or diseases and treat the tree if any are found.