Aphids on Magnolia tree are attracted by the trees’ beautiful flower colors and scents, giving both amateur and experienced gardeners headaches. Your magnolia could also have aphids due to high nitrogen levels and plant weaknesses.A Full Article About Aphids on Magnolia Tree PlantAmericaYou can eliminate these bugs by washing them with water, neem oil, or pesticides. Continue reading this full guide for more details!

Why Are There Black Aphids on Your Magnolia Trees?

There are black aphids on your magnolia trees because of their attractive flowers and new leaves, high nitrogen levels, and weeds that are growing near the tree. Weak magnolia trees can also be a cause of aphid infestations, as well as a lack of natural predators.

Magnolia trees have large, showy, nicely scented flowers, which are a major attraction to humans and aphids. But these insects don’t crawl and fly miles to admire and smell magnolia flowers; they feed on the plant sap, which leaves the plant weak and stressed.

Aphids also attack magnolias because of their new leaves. The young foliage is easy to chew and tear through to reach the plant sap. Furthermore, phloem in these young leaves is fresh and sweet, drawing more insects to the plant. And as they feed and get satisfied, they reproduce and multiply more.

Another reason you have white aphids on magnolia trees is because of plant weakness. Plants get weak due to insufficient essential minerals or insufficient water. This makes magnolia flowers more vulnerable to insect attacks. See more reasons for aphid attacks on magnolias below.

– Attractive Flowers and New Leaves

As unreal as it might sound, aphids are attracted to big, bright flowers like humans. The flower petals are mostly velvety soft, which makes it easier for aphids to tear through and get the cell sap. This could be why you have aphids and scale insects on your plant.Causes of Aphids on Magnolia Tree PlantAmericaWhen aphids attack magnolias, they feed on the sap in the flowers, weakening them. Excessive sap removal weakens the entire plant, and the leaves could turn yellow and wilting. And since aphids multiply fast, a greater infestation leads to high amounts of cell removal, which can kill the plant.

Besides the attractive flowers, aphids are also drawn to plants with new leaves. This happens because new leaves are soft and easy to chew on. The leaf’s softness makes it easier for the insects to tear through and suck on the sap.

While new leaves on plants are a win for the gardeners, you must constantly inspect if there are insect infestations. Gardeners of new seedlings should be extra careful because the tiny plants can quickly die from the sap removal.

– High Nitrogen Levels

As a new magnolia plant parent, you will find that nitrogen is one of the most essential nutrients. It ensures plant growth by supporting photosynthesis, which provides energy for development. And it is because of nitrogen that you have new leaves in your magnolias.Nitrogen Chemical Profile On a Table PlantAmericaHowever, the nutrient can have some adverse effects if overused. Nitrogen makes a good breeding environment for aphids. They lay perfectly healthy eggs in such soils and go through their life cycles without interference in such environments.

Also, high nitrogen keeps plants growing, meaning new magnolia leaves will constantly be produced. And since aphids feed on the new plant leaves, they will have a constant food supply. This keeps them in your magnolias, and since they are full and content, they reproduce fast, increasing their population.

– Weeds Growing Near the Magnolias

While you can grow magnolias indoors, some varieties require outdoor spaces. One mistake gardeners make when growing magnolias and other plants is leaving them to choke between the weeds. Magnolia scale bugs hide in these weeds and slowly transfer to your flowers.

The problem with having weeds in your garden is that they provide perfect hiding and breeding zones for insects. Some weeds have large leaves that house these tiny insects, and they lay eggs inside the leaves. Gardeners will hardly notice when these insects are breeding.

Also, weeds provide food for insects. Some have soft-to-chew leaves, while others have a sweet sap that aphids feed on. As the aphid population increases, food in the weeds decreases, and the insects slowly migrate to the magnolia garden.

– Weak Plants

If you have not provided the proper tree care for your magnolias, they become weak and stressed. Brown aphids on magnolia trees infest because the weak plants have flaccid leaves because of the reduced turgor, which are easier to chew on. Also, these plants cannot fight infections and insect infestations.Reasons of Aphids on Magnolia Tree PlantAmericaPlant weakness is caused by underwatering, overwatering, transportation, or transplantation. It could also be due to little nutrients caused by neglect. Besides, the presence of weeds in the garden is another cause of plant weakness because the unwanted plants intake most nutrients and minerals, leaving magnolias with only a few to survive on.

– Lack of Natural Predators

Compare-n-save systemic tree and shrub insect drench and Bonide Products Inc systemic insect control 941 are perfect for pest control. Aside from that, some natural predators also feed on the insects. These include ladybirds, lacewings, and hoverflies, and they occur naturally.A Close Shot Of a Hoverfly on a Leaf PlantAmericaThese natural predators control pests at the earliest stages of the attack before the gardener is aware. So a lack of predators will lead to a fast infestation. Aphids infest in small colonies, but they reproduce fast, leading to a heavier infestation that causes worse damage.

How To Get Rid of Aphids on Magnolia Trees

To get rid of aphids on magnolia trees, you can use pesticides, remove the weeds around the plant, reduce nitrogen fertilization, use neem oil, spray water to get rid of the insects, manually handpick and crush the bugs, and introduce some natural predators.

Once you have identified the cause of aphids on your magnolias, you can quickly eliminate them from your garden. If you suspect the attack was because of the weeds, ensure you remove any unwanted plants from your garden. You should also keep the plants healthy and get natural predators.

What if the bugs attacked the trees due to other reasons? You may be asking “How do I keep bugs from eating my magnolia leaves?” You can use other pest control methods like insecticides and pesticides to kill aphids. If not, use milder ingredients like insecticidal soap and neem oil, or pick and crush the aphids with your hands.

– Use Pesticides

Aphids don’t bother most gardeners because they are known to be less destructive insects. However, a heavy infestation can cause massive damage, and you need an effective control method. Most gardeners will spray pesticides on their magnolias, but you must be selective with the pesticide.Gardener While Using Pesticide With White Container PlantAmericaFor example, if you have a heavy aphid infestation on your magnolias, apply the hi-yield systemic insect granules. These are applied to the soil and absorbed by the roots into the entire plant. When the insects chew on the plant leaves or suck the sap, they ingest the product and die. You can also use the Bonide insect control systemic granules to keep aphids off.

Before applying these chemicals, consult a professional first to avoid hurting your plants. The pesticides are made with a mixture of strong chemicals, which can scorch the plants if misused. If you are applying the chemicals on your own, test them on a few plant leaves to see their reaction first.

– Remove Weeds

If you found the cause of aphids in your garden to be weeds, remove them. You can dig them out using weeding tools like hoes or spray chemicals to kill them. Again, be selective with the chemicals you use because some can kill your plants.Solutions of Aphids on Magnolia Tree PlantAmericaIt is safer to consult a professional to guide you on the right weeding chemicals. The professional will also help with the application, saving you time and the danger of suffering skin irritations. Removing the weeds leaves the plants healthy and less vulnerable to aphid attacks.

– Reduce Nitrogen Fertilization

Another way to keep aphids off your magnolias is by reducing nitrogen fertilization. Nitrogen supports aphid growth and reproduction and keeps the plants constantly growing. When new leaves are continuously produced, aphids will have a constant food supply, which keeps them in the garden.

Reducing nitrogen fertilization slows down the plant growth. Since there won’t always be new leaves, the insects could starve and die. Low nitrogen levels also make the area unconducive for aphid survival, which means they will start migrating.

– Use Neem Oil

Are you still wondering how to treat aphids on magnolia tree? Neem oil is a Bonide systemic insect control method that doesn’t affect the plant. The oil has azadirachtin, which is absorbed by the plant to contaminate its roots, stems, and leaves.

As the insects chew on the leaves, they ingest azadirachtin, which interferes with the reproduction of their hormones. The ingredient also disrupts the aphid life cycle, killing most insects as they transition to their next stages.

Aside from that, neem oil also suffocates aphids. When sprayed directly on the insects, it blocks their breathing pores on the thorax and abdomen, killing them by suffocation. Lastly, the oil can damage the insects’ cuticle, exposing its membrane and killing its cell constituents.

– Spray Water on the Magnolias

High-pressure water is a suitable pest control method, especially for tiny insects like magnolias. The insects are small and have little energy to support themselves on the leaves, so if you pass water over them from a high-pressure sprayer, they will all fall and drown.Cures of Aphids on Magnolia Tree PlantAmericaThis aphid control method doesn’t have side effects since it doesn’t include chemicals, but you must be careful when using it. For example, don’t set the hose pipe to a very high pressure because this could cut the flowers and leaves.

Also, don’t pour a lot of water on the plants when trying to get rid of the aphids. This leads to overwatering the plants, causing worse problems like root rot. You can let the soil dry a few days before the next spraying.

– Hand-pick the Insects

If you have seen two or three aphids on your magnolias, you don’t need water to drown them. Instead, you can manually handpick them and crush them between the fingers. Killing a few insects prevents breeding and protects your garden from aphid infestations.

You can pick the aphids using a paper towel to avoid getting into contact with them. Also, don’t crush them between the leaves. The friction hurts the leaf cells, leaving open wounds that could make way to infections. Once you crush the insects, drop them in a trash bin and burn them. This prevents reinfestation and ensures the insects are entirely dead.

– Introduce Natural Predators

Since a lack of natural predators can lead to aphid infestation, you can introduce some predators to your garden. Buy lacewings and ladybirds from the nearest plant store, and let them free into your magnolia garden. They feed on the young and adult aphids, reducing the population. A Closure For Aphids on Magnolia Tree PlantAmericaThese insects also kill the aphid eggs before they hatch, regulating their population.


Aphids on magnolias can be due to weak and stressed plants, lack of natural predators, overfertilizing with nitrogen, and the presence of new leaves. You can try the ways mentioned above of treating aphids to eliminate them, and some crucial points you have learned are:

  • Aphids are less feared insects because they don’t cause tremendous destruction, but a significant infestation can lead to plant death.
  • You can kill aphids using other predator insects, picking them by hand, or using chemicals like pesticides and insecticides.
  • If you use chemical means of eliminating aphids, hire a professional to spray them to avoid hurting your plants.

Now that you know the reasons for aphid attacks and the different ways to eliminate them, you can take action to save your flowers today!

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