Leaves covered in a sticky substance, black sooty mold, and/or yellowing of leaves are all signs of a greenfly or aphid infestation.
What are aphids? Otherwise called greenflies or plant louse, aphids are small, soft-bodied insects that suck the sap out of plants, using their piercing mouthparts. They may also transmit viruses from one plant to another .
So, what are some of the most effective ways of keeping them away without using toxic chemicals?
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 any in a gallon of water and spraying your plants, can repel green flies. 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 greenfly? Yes, it does. These bugs have a waxy-like substance on their backs, and when mixed with soapy, hot water, it will dissolve.
Consequently, they will later become dehydrated and die. This method can also kill beneficial bugs, so be careful not to spray them too.
Look for natural premixed liquid soaps like Dr. Bronner’s. Mix a small amount (about four tablespoons) in a gallon of water and spray affected plants.
4. 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 bad bugs. Read Epsom Salt for Plants: Ease Your Gardening Woes.
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 so they don’t get burnt when the sun comes out.
5. Garlic Spray
A homemade aphid spray can get the job done. All you’ll need is some mineral oil and fresh garlic.
Firstly, chop four cloves of fresh garlic cloves and let them sit overnight in two teaspoons of organic mineral oil. Secondly, take out the solid garlic pieces and add the liquid to two cups of water.
Thirdly, add a teaspoon of organic liquid soap to the mix. Finally, shake well and spray the solution on your plants.
This repellent spray will force them to stay away as they hate the smell.
6. Vinegar Solution
Vinegar is a natural household product that is commonly used to deter garden pests.
Combine one tablespoon of liquid soap with four tablespoons of vinegar in a gallon of water. Afterward, add to a spray bottle and coat affected plants.
7. Diatomaceous Earth (DE)
Diatomaceous earth is a powdery substance from the fossilized remains of small aquatic organisms.
If applied correctly, this killer remedy will get rid of them permanently. DE is toxic to green flies — it will enter their system and dehydrate them.
However, purchase a brand that is OMRI listed for safe use in organic farming. Lightly dust the leaves of affected plants and reapply once there’s a heavy downpour of rain.
8. Hose Them
Believe it or not, one way to keep away stubborn pests is to use the hose. Select the hard jet-setting and spray away at your leaves.
Of course, it is important to make sure you don’t damage the plant 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 — keeping them happy while also keeping your crops happy.
If the critters are happily eating elsewhere, they will hopefully leave your garden alone.
Trap crops include cosmos, hollyhocks, verbena, and zinnias.
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 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
This can serve as a general pest deterrent by putting aluminum foil or reflective mulch on the ground underneath your plants.
It also serves a dual purpose as it can help 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.
In this case, it is essential to take time out in your garden and identify which bugs need removal from the plants.
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 bad bugs themselves, but also make sure to get the eggs. Remove them from the leaves and squish them.
Destroying greenfly eggs will help keep your crops safe from harm. While the eggs are not an immediate threat, as soon as they hatch, the new bugs will wreak havoc on your plants.
15. Pay Close Attention to the Ants
Pay close attention to ants. Aphids and ants are like best friends; therefore, they are sometimes the culprits protecting them.
Consequently, 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
A great aphid control remedy, these guys hate the smell of onions. Puree one onion bulb in a cup of water to make a spray.
Strain and spray affected plants. You can 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?
They come in different colors — red, black, yellow, white, green, gray, or even pink, depending on species.
The green fly has 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 the juice out of 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 taking precedence in 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.