Milkweed flowers are some of the most complex plants you can have in your garden. These flowers are grown for ornamental purposes but their appealing aesthetics attract a range of pests such as aphids.
Milkweed is one of the flowers that are toxic to humans and other animals due to its milky inner substance.
Some insects rely on it, on the other hand. Butterflies and aphids such as the Milkweed aphid need milkweed for food and to multiply.
You can get rid of aphids on milkweed by introducing predatory bug species such as ladybirds. Alternatively, you can plant marigolds that deter aphids or spray neem oil on milkweed to deter aphids without using insecticide.
One of the main problems when trying to control aphids on milkweed is the use of an insecticide. This chemical solution is not healthy for the flowers and it may even kill them when used in excess.
As a result, all other natural solutions need to be considered individually or together.
Which aphids eat milkweed?
Aphids can eat multiple types of flowers. They suck nutrients out of flowers to the point they can kill them, especially with a serious invasion.
Oleander aphids (Aphis nerii)
Oleander aphids are among the few species that only eat plants and flowers such as milkweed, oleander, and butterfly weed.
These aphids have a yellow-orange color and black legs.
Multiplication rates are high to very high in Oleander aphids which can reproduce without sexual contact. Female Oleander aphids reproduce on their own, creating genetically-identical small female aphids.
What is milkweed?
Milkweed is a herbaceous plant of the Asclepias genus. It produces glycosides that resemble milk when damaged.
There are more than a few hundred milkweed species around the world. Many of them suffer from considerable aphid invasions.
9 methods to get rid of aphids on milkweed
Since Oleander aphids reproduce on their own without mating, these bugs can quickly overcrowd milkweed. From stunted growth to eventually killing the plant, these aphids need to be removed right away. Here’s what you can do.
1. Use predatory ladybugs
Ladybugs are a predatory species that feed on aphids. Most types of ladybugs are carnivores and they need to eat insects and other bugs to survive.
You can buy ladybugs in their thousands and release them in the garden or on the farm where you have an aphid invasion.
Ladybugs are so efficient at killing and eating aphids that you should not see a single aphid left by the end of the summer.
Some ladybugs are not going to stay around the garden, so it’s best to purchase more than you initially need, especially when growing milkweed for commercial purposes.
2. Plant deterring marigolds next to milkweed
Deterring plants have their role in the garden. They might not be the first planting option but they help keep bugs and insects away from the plants, fruits, and vegetables you like.
Marigolds are among these flowers you can consider to deter aphids. The flowers have a proven deterring effect from the second year.
This means you should plan to plant marigolds before you get an aphid invasion on milkweed. Once marigolds have established themselves in the garden, they can deter all types of aphids.
Marigold planting location or frequency depends on the number of milkweeds you have. Ideally, you place one marigold every 2-3 milkweeds. This is how you know these flowers can add the protective barrier needed against aphids.
Planting marigolds further away from milkweed has no effect. Aphids know they can live on milkweeds that are just a few feet away from marigolds which they don’t touch.
3. Spread out sticky bug traps
Sticky traps are sometimes considered against Oleander aphids in small gardens. Aphids are attracted to bright colors so you can specifically choose white or yellow sticky traps.
These types of traps are spread out around the garden, especially in the area where milkweed grows. As a result, you can often find these traps completely covered in aphids due to their high efficiency.
Various aphid traps are available on the market. The most successful traps are made from a simple piece of colored and sticky cardboard.
This cardboard is added next to milkweeds vertically. You can stick the traps in the ground around the garden if you have more than a few milkweeds.
4. Spray neem oil
Essential oils are sometimes used against invasive species such as aphids. Natural essential oils successfully deter and even kill certain species of aphids.
Neem oil is one of the essential oils recommended for milkweed, roses, tulip, and other flowers. It keeps aphids away successfully.
Some aphids may even die when you spray neem oil or other essential oils directly on them. You need to mix essential oils with water and spray the plant completely for this solution to work.
You should not use a large amount of neem oil. The ratio is 5-10 drops per bottle sprayer which should be enough to completely spray more than a few milkweeds.
However, the best chance to use essential oil is to spray milkweed before the aphid season begins (early spring). Other essential oils successfully used against aphids include the following.
- Lavender essential oil
- Eucalyptus essential oil
- Rosemary essential oil
All of these alternative essential oils are also sprayed in a diluted form to protect milkweed.
5. Spray orange peel
Orange peel is believed to cause negative reactions in aphids. They hate oranges and the peel is where most of the aroma is truly concentrated.
Orange peel has sometimes been laid around milkweed as compost. But spraying it is best as it covers the entire milkweed flower, stem, and leaves.
You can add orange peel to a sprayer bottle and spray all milkweed plants, including the roots. Its effect is similar to the effect of essential oils.
6. Consider washing plants with soap and water
Watering milkweeds is recommended for healthy flowers. But watering them with soap and water is one of the methods people use to keep Oleander aphids away.
A small amount of soap is mixed with water and then sprayed on the entire herbaceous plant. You need to evenly coat the plant in water and soap.
This process is repeated at least twice per month so that soap doesn’t get completely washed away whenever it rains.
You should also refrain from spraying chemical-based soaps on milkweed. Natural ingredient soaps are best.
7. Sprinkle diatomaceous earth
Diatomaceous earth is a type of rock that occurs naturally. It’s often used instead of insecticides as it has the same effects in the garden.
This type of rock is sold in a granulated form which can be applied at the root of the plant. Safe to use compared to insecticides, diatomaceous earth might need to be sprinkled around milkweed each year.
The end of the winter and the beginning of the spring is the best time to add diatomaceous earth to your milkweed.
8. Use plant covers
Plant covers are among the necessary actions when it comes to stopping potential aphid invasions. These aren’t needed for the entire season as they’re mostly used in the spring when Milkweed aphids are most active.
Plant covers can stop all types of plant pests from your garden. They can be removed just for watering the plants.
You can consider various mesh-type plant covers if you solely rely on rainwater for your milkweed.
9. Remove aphids by hand
Aphids don’t bite. This means you can remove them by hand, one by one. This can be a laborious task that can take hours for just a few milkweeds.
On the other hand, removing aphids by hand is one of the few certain methods to clear out milkweeds yourself. This can be an option if you only have a few milkweeds around the garden.
You can get rid of aphids on milkweed by looking for alternative methods to insecticides. Natural solutions such as essential oils or introducing aphid predators such as ladybugs are among the most efficient alternatives.
Even removing aphids by hand can be a solution if you only have a few milkweeds. Aphids don’t bite and they don’t transmit diseases to humans which means you can easily remove them by hand.
Oleander aphids are commonly seen on milkweed. The species has a yellow-orange color which makes for quick identification.
These aphids are known for being one of the parthenogenesis aphids. It reproduces asexually and it does it at a very high rate as the females that lay eggs don’t need to look for males to reproduce.
As a result, quickly removing aphids by hand is crucial. Once a female has landed on milkweed, reproduction can start. The availability of food makes females lay tens of eggs at once. The eggs are laid directly on milkweed or at the plant’s roots. Newly emerged aphids can begin feeding on the plant immediately.
Failing to remove these aphids leads to slower growth rates in milkweed. In case of serious infestations, milkweeds begin to die within a few days. They can also die slowly when only invaded by a few aphids.