Stems or leaves covered in a sticky substance, curling, wilting, or yellowing of leaves are all signs of a greenfly or aphid infestation.
Otherwise called greenflies, aphids are small, soft-bodied insects that suck sap from plants. They may also transmit viruses from one plant to another .
Here’s how to get rid of greenfly (aphids) naturally.
1. Neem Oil
Neem oil is excellent for killing aphids naturally.
Combine one tablespoon of neem oil suitable for garden use with one tablespoon of liquid castile soap in a gallon of water. Next, pour it into a bottle and spray your plants.
Another option is to boil neem leaves until the water changes color. Afterward, let it sit overnight then strain out the particles and add to a spray bottle.
2. Essential Oils
Essential oils have many different jobs, and one of those is to keep pests out of the garden. Anise, basil, fennel, peppermint, and pennyroyal essential oils all work against aphids 
Mixing two ounces of essential oil in a gallon of water and spraying your plants can get rid of aphids organically. Not only does it kill those small green bugs that fly, but it will stifle the eggs too.
3. Soap and Water
Does soapy water kill aphids? Yes, it does. These insects have a waxy-like substance on their backs, and when mixed with soapy water, it will dissolve. Consequently, they will become dehydrated and later die.
Look for natural premixed liquid soaps like Dr. Bronner’s. Mix 3-4 tablespoons in a gallon of warm water and spray affected plants.
Use this method to get rid of greenfly on houseplants, roses, and other indoor and outdoor plants. However, it can also kill beneficial bugs, so be careful not to spray them too.
4. Epsom Salt
Another great home remedy to kill green flies is Epsom salt.
Add two tablespoons of Epsom salt and two teaspoons of liquid soap to a gallon of water. By spraying the mixture onto plants, you can repel other bad bugs as well.
However, it is best to use it on the underside of the leaves early in the evening. After the night has passed, rinse off the leaves with a garden hose. Read more on how to use Epsom salt on plants.
5. Garlic Spray
All you’ll need to make this homemade greenfly spray is some mineral oil, fresh garlic, a teaspoon of liquid soap, and two cups of water.
Chop four cloves of fresh garlic and let them sit overnight in two teaspoons of organic mineral oil. Next, take out the solid garlic pieces and add the liquid to the two cups of water.
It’s now time to add the liquid soap to the mix. Some people use regular dish soap but we prefer using organic liquid soap in all our recipes.
Finally, shake well and spray the solution all over your plants. This repellent spray will force greenflies to stay away as they hate the smell.
6. Vinegar Solution
Household vinegar is a product that is commonly used to deter garden pests like plant lice.
To make a natural aphid spray using vinegar, combine one tablespoon of liquid soap with four tablespoons of vinegar in a gallon of water.
Add to a spray bottle and use it to coat the affected plants.
7. Diatomaceous Earth (DE)
Diatomaceous earth is a powdery substance that is made from the fossilized remains of small aquatic organisms. DE is toxic to green flies. It will enter their system and dehydrate them.
This killer remedy also works to get rid of other bad plant bugs organically. However, purchase a brand that is food-grade or OMRI listed for safe use in organic gardening.
Lightly dust the leaves of affected plants. Alternatively, make a homemade aphid spray by combining 5 tablespoons of diatomaceous earth in a gallon of water.
Use it to coat the affected areas but ensure it is not heavily dripping. Also, reapply once there’s a heavy downpour of rain.
8. Hose Them
Another effective home remedy to keep away stubborn pests is to wash them off with a garden hose.
Select the hard jet-setting and spray away at your leaves. However, use this DIY method with caution to avoid damaging your plants in the process.
9. Plant Other Plants
Trap cropping is a clever pest control method.
There are some plants that you can plant in your yard to attract harmful insects. These trap crops keep the pests happy, so they will stay away from your main crops.
Plants that attract aphids include nasturtiums, mustard, stinging nettles, and sunflowers.
10. Organic Commercial Pesticides
Perhaps the easiest and quickest way of getting rid of an aphid colony is to invest in safe and natural pesticides such as these:
These insecticides kill aphids and other soft-bodied insects naturally. Moreover, the products are OMRI listed, which means that they are safe for use in organic gardening.
11. Encourage Birds to Come Around
By putting out bird food in a feeder, you can attract birds that will help to control the bugs in your garden naturally.
Also, consider putting up birdhouses to attract various predatory birds like titmice, sparrows, chickadees, herons, and wrens.
12. Aluminum Foil
Placing aluminum foil or reflective mulch on the ground underneath your plants will deter these pests.
It also serves a dual purpose as it helps retain soil moisture. Just remember to pick up the foil when the gardening season is over to protect the environment.
13. Remove Manually
If you only notice a minimal green fly infestation, you can remove by hand the bugs that you see.
Moreover, by dropping them into a tub of soapy water, they will suffocate without you having to squish them.
14. Squish the Eggs
Don’t just get rid of these pesky insects themselves, but also make sure to get the eggs. Remove them from the leaves and squish them.
Destroying greenfly eggs will disrupt their life cycle. While the eggs are not an immediate threat, as soon as they hatch, the new bugs will wreak havoc on your plants. No eggs mean no adult flies later on.
15. Pay Close Attention to the Ants
Pay close attention to ants. Aphids and ants are like best friends. As a result; they are sometimes the culprits protecting them.
Therefore, you might want to focus on getting rid of ants if you notice a large population in your garden. If there are no ants to protect the critters, there will be fewer to deal with.
16. Onion Spray
Another great aphid control remedy, these guys hate the smell of onions. Puree one onion bulb in a cup of water to make a spray.
Next, strain and spray affected plants to repel green flies. Use the measurement as a guide for bigger treatment concoctions.
17. Attract Insects and Bugs That Feed On Them
Some bugs and insects feed on other insects. However, it is important to know the ones that are beneficial from those that can damage your field.
Some of these useful predatory insects include ladybirds, lacewings, hoverfly larvae, aphid midge, and parasitic wasps.
What do Aphids Look Like?
The critters come in different colors — red, black, yellow, white, green, gray, or even pink, depending on species. They also have a soft and waxy pear-shaped body with long antennae.
What do Aphids Eat?
By living on crops, they can damage the leaves, stems, fruits, or roots. Green flies are herbivores that suck sap from plant parts.
Adults and baby aphids target most fruit and vegetable crops and some flowering plants like roses, pansies, lupins, and petunias. Additionally, kale, basil, lettuce, pak Choy, tomatoes, arugula, raspberries, and pepper plants are their favorite vegetables.
These natural home remedies and products can correct the problem and prevent all sorts of insect pests from infesting your garden.
You can also talk to the professionals at your nearest garden center. They can give you advice on which plants might be less affected by the greenfly insect in your particular climate.