Get Almanac's Daily Updates Extended Forecasts Where to Buy Contact Us

How to Identify and Get Rid of Aphids on Plants

green aphids crawling on a plant

Aphids are pesky green bugs that can wreak havoc on your garden.

Photo Credit
Pixabay

Preventing Aphid Infestations in Your Garden

Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

What are those little green bugs on your plants? They’re probably aphids! Here are our best tips for identifying and getting rid of aphids in your garden.

What Are Aphids?

Aphids seem to find their way into every garden. They are small, soft-bodied insects that feed by sucking the nutrient-rich liquids out of plants. In large numbers, they can weaken plants significantly, harming flowers and fruit. Aphids multiply quickly, so getting them under control before reproduction starts is important. Many generations can multiply in one season.

Lee Townsend, an Extension Entomologist at the University of Kentucky College of Agriculture, explains, “Infestations generally result from small numbers of winged aphids that fly to the plant and find it to be a suitable host. They deposit several wingless young on the most tender tissue before moving on to find a new plant. The immature aphids or nymphs that are left behind feed on plant sap and increase gradually in size. They mature in 7 to 10 days and then are ready to produce live young. Usually, all of them are females, and each is capable of producing 40 to 60 offspring. The process is repeated several times, resulting in a tremendous population explosions. Less than a dozen aphid “colonizers” can produce hundreds to thousands of aphids on a plant in a few weeks. Aphid numbers can build until conditions are so crowded, or the plant is so stressed, that winged forms are produced. These winged forms fly off in search of new hosts, and the process is repeated.”

The good news is that aphids tend to move rather slowly and, with diligent care, can be controlled.

Read Next

Identification

Identifying Aphids

Aphids are tiny (adults are under 1/4 inch), and often nearly invisible to the naked eye. Various species can appear white, black, brown, gray, yellow, light green, or even pink. Some may have a waxy or woolly coating. They have pear-shaped bodies with long antennae; the nymphs (young aphids) look similar to the adults. Most species have two short tubes (called cornicles) projecting from their hind end.

Rose Aphid on a plant
A close-up view of a rose aphid.

Adults are usually wingless, but most species can develop a winged form when populations become crowded, so that when food quality suffers, the insects can travel to other plants, reproduce, and start a new colony. Aphids usually feed in large groups, although you might occasionally see them singly or in small numbers.

While aphids in general feed on a wide variety of plants, some species of aphids can be specific to certain plants—for example: bean aphids, cabbage aphids, potato aphids, green peach aphids, melon aphids, and woolly apple aphids.

dark brown aphids on a leaf with a hand holding it
Some aphids are darker colors, like brown. The potato aphid is a common brown aphid. 
Photo credit: GrowVeg.com.

What Does Aphid Damage Look Like?

Nymphs and adults feed on plant juices, attacking leaves, stems, buds, flowers, fruit, and/or roots, depending on the species. Most aphids especially like succulent new growth. Some, such as the green peach aphid, feed on a variety of plants, while others, such as the rosy apple aphid, focus on one or just a few plant hosts.

  • Look for misshapen, curling, stunted, or yellowing leaves. Be sure to check the undersides of leaves; aphids love to hide there.
  • If the leaves or stems are covered with a sticky substance, that is a sign that aphids may have been sipping sap. This “honeydew,” a sugary liquid produced by the insects as waste, can attract other insects, such as ants, which gather the substance for food. When feeding on trees, aphids’ honeydew can drop onto cars, outdoor furniture, driveways, and so on.
  • The honeydew can sometimes encourage a fungal growth called sooty mold, causing branches and leaves to appear black.
  • Flowers or fruit can become distorted or deformed due to feeding aphids.
  • Some aphid species cause galls to form on roots or leaves.
  • Aphids may transmit viruses between plants.
  • Aphids also attract other insects that prey on them, such as ladybugs.
yellow aphids on a plant leaf
Aphids can be various colors, including yellow, and produce a sticky honeydew substance. 
Photo Credit: John Obermeyer/Purdue University.

Still not sure? Use our Plant Problem ID tool to easily diagnose pests and diseases.

Gardening Products

Control and Prevention

How to Get Rid of Aphids: Killing Aphids

  • Try spraying infested plants with a strong stream of water; sometimes, all aphids need is a blast to dislodge them. Typically, they are unable to find their way back to the same plant.
  • Neem oil, insecticidal soaps, and horticultural oils are effective against aphids, but these substances need to come into contact with the aphids in order to work. Be sure to follow the application instructions provided on the packaging.
  • You can often control aphids by wiping or spraying the leaves of the plant with a mild solution of water and a few drops of dish soap. Soapy water should be reapplied every 2-3 days for 2 weeks.
    • One variation of this soap-water mix includes cayenne pepper: Stir together 1 quart water, 1 tsp liquid dish soap, and a pinch of cayenne pepper. Do not dilute before spraying on plants.
  • Diatomaceous earth (DE) is a nontoxic, organic material that will dehydrate aphids.
    Warning: Do not apply DE when plants are in bloom, as it will kill pollinators such as bees and butterflies if they come into contact with it.
thumb over the end of a garden hose spraying water
Hosing down your plants is one way to control the aphid population in your garden.

How to Prevent Aphids

  • For fruit or shade trees, spray dormant horticultural oil to kill overwintering aphid eggs.
  • Beneficial insects, such as ladybugs, lacewings, and parasitic wasps, will feed on aphids. Attract these insects to your garden by providing an environment that features a range of flowers and foliage plants, as well as access to water. Supplemental populations of these insects can be ordered online and should help control the aphid populations from the start.
  • Companion planting can help keep aphids away from your plants in the first place, or can draw aphids away from the plants you want to grow. For example:
    • Aphids are repelled by catnip.
    • Aphids are especially attracted to mustard and nasturtium. Plant these near more valuable plants as traps for the aphids. The aphids will likely go for these plants before your prized tomatoes. (Check your trap plants regularly to keep aphid populations from jumping to your valued plants.)
    • Nasturtiums spoil the taste of fruit tree sap for aphids and will help keep aphids off of broccoli.
    • Garlic and chives repel aphids when planted near lettuce, peas, and rose bushes.
Ladybug larva
Ladybug larvae look scary, but they are one of the top aphid predators. If you see them on your plants, leave them be! 

Using Alcohol to Control Aphids

Isopropyl alcohol (also called isopropanol or rubbing alcohol) works fine and is easy to find, but be sure it doesn’t have additives. Ethanol (grain alcohol) seems to work best. Alcohol usually comes in 70 percent strength in stores (or 95 percent strength purchased commercially). To make an insecticidal alcohol solution, mix equal parts 70 percent alcohol and water (or, if using 95 percent alcohol, mix 1 part alcohol to 1 ½ parts water). 

You can also add alcohol to a soapy emulsion to make it more effective. For example, in a spray bottle, combine 5 cups water, 2 cups isopropyl alcohol, and 1 tablespoon liquid dish soap. 

These types of solutions should NOT be sprayed over the entire plant at once. Spray or wipe down only the infested areas. It will only kill the aphids it comes into contact with, so repeated applications may be necessary.

CAUTION: When applying an alcohol or soap spray, or a combination, always test on a small area of the plant first, and apply in the morning or evening, when the Sun is not as intense. Watch the plant for a few days for any adverse reactions before applying more. Plants can be sensitive to alcohol and dish soap. Also, some soaps have additives that can damage plants—select the purest form.

Check out this video to learn more about how to get rid of aphids:

Do you have more tips for controlling aphids? Let us know in the comments below!

Garden Pests
About The Author
Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the website companion of The Old Farmer's Almanac. She covers gardening, plants, pest control, soil composition, seasonal and moon c...
Read More from Catherine Boeckmann

More Like This

Comments

<a title="View user profile." href="/author/editors">The Editors</a> Wed, 02/11/2015 - 13:43
To make a garlic solution to combat aphids, mince a few cloves of garlic into 2 teaspoons of mineral oil. After a day, strain out the garlic pieces and add what's left to one pint of water. Add one teaspoon of liquid dish soap. When you apply the solution, you can dilute it down with water in a spray bottle (about 2 tablespoons garlic to 1 pint water). It's organic and safe.
<span>Shirleen Molenhouse</span> Fri, 11/07/2014 - 13:22
I have a hibicus tree that i have treated for aphid but they keep coming back...I have used water and dishwashing soap and sevin and horticultural oil at different of course and got rid of them 2 times so they must be in the soil so what can i do to kill the ones in the soil? this is a house plant...I have spent more time and energy on this plant than any other plant in my life......this has been going on since may...
<span>Bud Martin</span> Sat, 06/06/2015 - 19:32
change the soil it's planted in change the pot it's growing in treat the leaves for aphids once more problem should be gone make sure you rinse off the roots
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 11/11/2014 - 07:14

We would advise washing regularly, avoid over fertilization, and use insecticidal soaps or horticultural oils (neem oil). However, if this has failed, you might want to turn to more serious insecticides or actions (bifenthrin, permethrin, resmethrin, disulfoton, imidacloprid). Speak to your garden center.

 <span>Morgen</span> Tue, 10/14/2014 - 11:42
I just found what looks like a green aphid. I had no experience with green ones before. I have a cutting from a black raspberry plant that is infested. I didn't notice any insects when I brought it in. This is in my "green room" where I'm propagating plants so it could be a disaster! I have lots of succulent cuttings taking root in there. I will try the NEEM oil I have along with the soap/alcohol/water/cayenne solution. I will paint or spray all my plants, just to be sure. I tried a soap/vinegar/epsom salt solution for weed control and it worked very well, so I'm sure this will work just as well. Thank you for everyone who posted!
<span>Vanessa Hee</span> Tue, 09/02/2014 - 22:37
I have two chilli plants kept on a window sill..and I recently noticed some of their leaves were sticky and started to curl inward. I noticed on the underside some small white spots of things that moved. I've made and tried the rubbing alcohol+water+soap formula right now..How often should I be spraying it on the leaves? Do i leave it to dry or do i have to wash out the liquid on the leaves aftwr a while? And do I spray on both sides?
<span>Tony Klose</span> Mon, 06/22/2015 - 02:54
I had a TON of green aphids feeding on a tiny jade plant. I took a spray bottle with about a 1:1 mixture of water and 91% isopropyl alcohol and a little dish soap. (I would use more alcohol if you only have the 70% kind). I sprayed the plant thoroughly on the stems and both sides of the leaves and I thought nothing had happened, but then I took a q-tip and wiped some of the aphids off and they appeared to be dead! I'm guessing the dish detergent acts as a wetting agent that either helps to drown the aphids, or helps get the alcohol onto/into them which perhaps does the killing. Either way, I wiped the rest of them off but I have to see if they'll make a comeback yet.
<span>Vishnu</span> Wed, 09/03/2014 - 14:23
I mix with water,soap and rubbing alcohol then spray I will see next day if will gone for good what if they come tiny white bugs on my hot pepper
<span>Sheena</span> Fri, 08/22/2014 - 04:06
Hello:) my organic veggies (yellow+green squash), peppers,tomatoes, pumpkins, watermelon+Marigolds are in 1 area I am asking about. I hav 1 pumpkin w black dust on part of the skin. So far 1/2 of it+a few leaves turning yellow. We use our llama-doo+they all grow like magic!I can look into which pest is causing said issue. My ? Is I have many happy Lil frogs working on the leaves to eat pests:). So I won't use anything that may harm frogs, bees, butterflies or birds and lady bugs etc! Won't these sprays burn them?:(. We have a large wildlife habitat+ponds. With many frogs, turtles, ducks, geese and wildlife. Plus chickens in same zone as this raised bed that's growing like magic! We have Ants around but do our best to just vinegar and rinse the ones that enter the home or bother pets. Cinnamon isn't safe for pets, nor are onions and garlic. I have tons of peppermint with some being 5 feet away. We have many fruit orchards+vines. Iset up frog habitat in that plot+they adore being there. I have Peppermint Castile Soap but won't it burn my eco pal's? The BlackBerry vines have grown and migrated within 3 feet of the plot. Ahh:)," its like Jack's Magic Stalks from the llama-doo! Strawberries, Blueberry bush, Figs, Lemons, Oranges, Apples, Cherries, Grapes, Pears,Loquat+more are all about our place. We have many Weeping Willows are there any solutions from any of these that may help my possible Flea Beetle and or Mites or whatever? I will do the work as long as it won't hurt:) THANK U!:)
<span>Linda Zero</span> Fri, 08/29/2014 - 10:02
My aphids (black) are out of control. They are ruining my zucchini and okra plants. My question is: can I cut the bad leaves of the plant? My okra is still producing but my zucchini plants are suffering bad from the aphids. They have damaged the fruit to non edible fruit. And I'm asking when they get this far gone do I just pull up the plant.