How to Get Rid of Aphids on Trees, Home Guides, SF Gate
How to Get Rid of Aphids on Trees
- 1 How to Get Rid of Aphids on Trees
- 2 Aphids, how to get rid of them?
- 3 Effective organic aphid treatments
- 4 Smart tip about aphids
- 5 How to kill Aphids
- 6 Remove the Pests by Hand
- 7 Release Aphid Predators
- 8 Make and Use Insecticidal Soap
- 9 Step 1: Mix the Concentrate
- 10 Step 2: Store the Concentrate
- 11 Step 3: Prepare the Concentrate for Use
- 12 Step 4: Dilute the Concentrate
- 13 Step 5: Apply the Mixture
- 14 Step 6: Repeat as Needed
- 15 Apply Horticultural Oil
- 16 Protecting Roses from Aphids and Other Common Pests
- 17 Aphids
- 18 Rose Chafers
- 19 Roseslugs
- 20 Japanese Beetles
- 21 Scale Insects
- 22 Effective Pest Control
- 23 The Tree Center
- 24 How To Get Rid Of Aphids
- 25 Preventing Aphids From Colonizing
- 26 Getting Rid of Aphids
- 27 Comments 24 comments
Brown, mottled leaves often indicate an aphid problem.
Nearly all plant life attracts aphids. These soft-bodied, pear-shaped insects measure a little under 1/4 inch long and have two long, slender antennae with small bumps, known as tubercles, at their base that aid in identification. Depending on which of the 5,000 or so identified aphid species are affecting your trees, you’ll find either yellow, brown, green, red or black insects sucking the plant fluid from your trees’ foliage and infesting the surrounding weeds. Although some aphids are beneficial, most cause severe damage and, despite a long list of natural predators, require a combined cultural and chemical approach for eradication.
Examine the insects you suspect are aphids and look for two horn-shaped protrusions on the posterior to confirm. These protrusions, referred to as cornicles, release defensive secretions and distinguish aphids from other insects.
Pull any weeds growing around the trees by hand. Aphid populations tend to build up in weeds such as mustard weeds and sow thistle.
Mix an insecticidal soap containing potassium salt of fatty acids as the main ingredient with the manufacturer’s recommended amount of water in a plastic or glass container. Alternatively, mix an insecticide containing one of the following active ingredients according to the manufacturer’s specifications: permethrin or malathion for food trees or acephate for non-food trees only.
Pour the diluted insecticidal soap or insecticide in a hand sprayer, pump sprayer or backpack sprayer. Shake the sprayer bottle or tank several times.
Apply the soap or insecticide to the tree’s foliage until saturated. Shake the container between sprays.
Wash and rinse the spray bottle or tank three times with dish soap and spray both the soapy water and rinse water through the hose or nozzle for 30 seconds each time.
Aphids, how to get rid of them?
Aphids are fearsome insects that attack leaves and feed on plant sap.
Leaves curl up and become sticky.
Key facts about aphids
Name – Aphidina
Common name – aphid
Appears in – spring, summer, fall
Favorable conditions – most plants might be attacked, but the weakest plants are the most vulnerable.
Having a garden brimming with insects, especially ladybugs, greatly helps control aphid populations.
Regular treatments against aphids will help you consistently eliminate them and keep them away from your plants and rose trees.
- Aphids are like the coronavirus for gardening: deal with small outbreaks fast to avoid large infestations!
Effective organic aphid treatments
Aphids attack many plants, rose trees and fruit trees in our gardens, and they can do considerable damage.
The following treatments can help fight aphids, and if one particular strategy doesn’t seem to work, you can apply several solutions together. Associating repellent plants and treatments is most effective.
- Since ladybugs eat aphid larvae, they naturally contribute to controlling aphid populations. This method is increasingly practiced by professionals who manage parks, and it is 100% organic.
Fermented stinging nettle or fern tea
It is sold now in horticulture stores but can be produced naturally too.
Fermented rhubarb tea
- Easy to prepare as early as April with fresh rhubarb leaves, here is our fermented rhubarb tea recipe.
- Made with Marseille soap or beldi soap dissolved in water and sprayed on the plant, this soap mix makes it hard for aphids to stick to leaves.
Grate 5 oz (150 grams) of soap and dissolve it in 1 quart (1 liter) water, add and mix in 1 tablespoon vegetable oil. Spray on plants.
Aphid repellent plants
- Planting aphid-trapping plants such as nasturtiums or aphid repellents such as French marigolds and above all lavender naturally helps control aphid populations (French lavender works, too).
- Fighting ants is necessary when they have established their nest.
Ants attract aphids and fuel their spread.
Here are good techniques to rid your garden of ants.
- These are excellent aphid predators, but they are only active from 60°F (16°C). They are rarely sold in horticulture stores.
- Products based on this plant can be used in organic farming. This is one of the main ingredients in aphid-control products sold on the market.
It is very effective and will mercilessly annihilate these parasites.
Special flowered lawn mixes are prepared these days, which repel most parasites and specifically aphids when the combination of flowers start to bloom.
- This flowered lawn mix can be sown in gardens and in the vegetable patch to protect vegetables.
Finally, a basic rule is to reduce use of chemical products as much as possible.
They usually wreck havoc in the local ecosystem, and weaken natural defenses that usually make plants immune to diseases and parasites.
Smart tip about aphids
Most damage occurs during the growth or vegetation phase, specifically in spring and at the beginning of summer. This is when treatments are most needed and effective.
How to kill Aphids
Aphids can cause a lot of damage. So if you spot them on your plants, it’s best to kill them right away. These tiny pests can be killed in several ways; choose the method that works best for your situation. Concoct a simple homemade solution or apply a commercial product to handle the problem.
Remove the Pests by Hand
Use a strong stream of water to knock aphids off your plants. A stream of water can fatally injure them, and those that live through the experience end up on the ground and aren’t very likely to find their way back onto plants. Repeat the process as often as you find aphids.
If the aphids are present in only small numbers, then either pick off the individual aphids and simply squish them or cut off affected leaves and destroy them along with the aphids.
Release Aphid Predators
Many insects eat aphids, and releasing these natural enemies of aphids into your yard or garden will help to kill aphids. Lacewings and lady bugs, or lady beetles, are among the insects that kill aphids. Because aphids reproduce very quickly, however, they may stay ahead of these predatory insects, especially if the aphid population is already well-established.
Make and Use Insecticidal Soap
Make your own insecticidal soap quickly and easily. The mixture will not only kill aphids by interfering with their cell membranes, it also will kill other soft-bodied pests such as whiteflies, mealybugs, citrus black flies and scale. Insecticidal soap must touch an aphid to kill it.
Not all plants tolerate insecticidal soap. It may damage some plants, according to the University of Colorado Extension.
Things You’ll Need
1 cup vegetable oil
1 tablespoon mild, liquid, dish-washing soap
Jar or bottle with lid
Step 1: Mix the Concentrate
Combine 1 cup of vegetable oil, such as corn, safflower, peanut or soybean oil, with 1 tablespoon of a mild, liquid, dish-washing soap, making an insecticidal soap concentrate. Don’t use ultra or concentrated dish-washing formulas.
Step 2: Store the Concentrate
Place the insecticidal soap concentrate in a jar or bottle that has a lid, and put the lid on the container. This mixture will be the basis of your insecticidal spray.
Step 3: Prepare the Concentrate for Use
Shake the concentrate just before you want to use it. Ensure its contents are thoroughly mixed.
Step 4: Dilute the Concentrate
Place 1 cup of tap water into a spray bottle, and add 1 to 2 teaspoons of the concentrate. Shake the spray bottle well to mix the ingredients.
Step 5: Apply the Mixture
Spray aphid-affected plants with the insecticidal soap-water mixture either in early morning or late afternoon, when the sun is not at its peak. Ensure that you spray enough of the solution to wet all the plant surfaces, including the leaves’ undersides.
Step 6: Repeat as Needed
Reapply the insecticidal soap solution weekly for two or three weeks if necessary.
Apply Horticultural Oil
Don’t apply horticultural oil in temperatures less than 40 degrees Fahrenheit or when a freeze is expected within one day.
An application of horticultural oil – available from plant nurseries and many home centers – can be used to kill aphids that spend winter on plants and then take over in spring. Put on protective clothing and gear that covers your skin, and mix 2 to 4 tablespoons of a horticultural oil concentrate with 1 gallon of water, and place the mixture in a handheld pump sprayer’s tank. Spray the oil-water solution on the plants before their leaves appear in spring. Spray all sides of the trunks and branches until they are completely wet. The solution will smother aphids. It is especially useful on fruit trees. Rinse out the sprayer with clean water when you are done.
Follow all label directions for horticultural oil, insecticide and any other product you use.
Wear protective clothing and gear to protect yourself from breathing or contacting horticultural oil or insecticide. Wear a long-sleeved shirt, long pants, waterproof boots, a hat, gloves, eye protection and a breathing mask.
Avoid spraying on windy days to minimize the treatment’s drift, and don’t spray when other people or pets are in the area.
Protecting Roses from Aphids and Other Common Pests
If wrinkled rose buds and puckered, curling new leaves appear on your roses, aphids are your primary suspects. Closer inspection may reveal tiny, green or pinkish soft-bodied insects feeding on succulent new growth. Aphids damage roses by piercing the plant tissue and then sucking out vital plant juices. They typically target soft stems, tender buds and new leaves. Thanks to aphids, roses that look fine one day can very suddenly become stressed and distorted.
One or two aphids may seem inconsequential, but aphid populations multiply rapidly. These pests have the unusual ability to reproduce without mating. Adult females bear multiple generations of live young that mature in as little as one week. 1 They can quickly overtake your roses and other garden favorites. Aphids also excrete a sticky substance known as honeydew, which attracts ants and other pests, and develops into unsightly sooty mold.
Large, irregular holes in rose petals and skeletonized rose leaves may signal rose chafers have arrived. You can identify these greenish tan beetles, typically about 1/2 inch long, by their spiky, red-orange legs and swift, extensive damage. Rose chafers target rose blossoms, but they also damage leaves, leaving the veins intact and devouring tissue in between. Small fruits on rose relatives, such as raspberries and strawberries, become targets, too.
Rose chafers are especially attracted to areas with sandy soil. Their larval stage is one type of the grubs that feed on grass roots and damage lawns. Adult chafers emerge from the ground in late spring to begin feasting on roses, but injury isn’t limited to plants. If eaten, rose chafers are poisonous to some small mammals and birds — including chickens in urban coops or agricultural settings. 2
Thin, translucent, paper-like splotches on rose leaves disclose that roseslugs were at work. These pests usually feed at night, so their unmistakable damage is often seen before they are. Roseslugs feed on the leaf surface without eating all the way through the leaf. A framework of thin papery “holes» and green leaf veins is left behind. This leaves the rose marred, weakened and susceptible to other pests and disease.
Roseslugs aren’t caterpillars, though there’s a resemblance. These yellow-green, wormlike creatures are the larvae of rose sawflies. Some species are smooth while others are bristly, but they typically grow up to 3/4 inch in length. 3 Roseslugs hatch from eggs laid by sawflies on the undersides of rose leaves. Damage begins when the first of many generations hatch in mid-spring. Roseslugs aren’t related to slimy garden slugs that frequent shade gardens, but they may cover themselves in a similar slimy film.
Large, ragged holes and rapid, rampant, late-spring damage may indicate Japanese beetles on the scene. These pests feed openly during daylight hours and are easily identified by their metallic green bodies, coppery bronze wings and small white dots ringing the outer abdomen. Typically 7/16 inch in length, these chewing insects favor roses. They skeletonize leaves and devour rose buds and blossoms in their entirety, leaving nothing but thoughts of what might have been.
Japanese beetles are invasive pests originally from Asia. With few natural checks in the United States, these devastating insects have steadily expanded their range across the country. In their larval stage, Japanese beetles are highly destructive lawn grubs that feed on grass roots and destroy turf. Adult beetles emerge from the soil in late spring and early summer. For the next four to six weeks, roses and other plants are subject to intense damage as beetles feast and emit signals inviting others to join them. 4,5
Your first clue to a scale problem is often a steady trail of ants across your driveway or sidewalk, headed straight for roses. Inspect rose stems closely and you may find collections of small «bumps» that, depending on color, almost appear like part of the rose. What you see is not the insect itself, but its protective covering. Some scales have a brownish gray armor, while others have soft, cottony coverings.
Scale insects pierce rose canes and suck out plant juices, causing stems to weaken, turn yellow and die back. Soft scales also excrete sweet honeydew favored by ants, which actually protect scales from beneficial insect predators to keep their supply flowing. Excess honeydew eventually develops into black sooty mold. Armor-free scale «crawlers» hatch and begin feeding on roses in spring. They are especially vulnerable to treatment at this unprotected stage. 5,6
Effective Pest Control
Giving your roses proper conditions and care goes a long way in protecting them against insect pests and diseases , but even healthy roses aren’t immune to attack. When rose pests strike, it’s important to take action at the first signs of pests or damage to preserve rose flowers and foliage.
Effective pest control is fast and simple with time-proven insecticides from Sevin ® brand . Sevin ® Insect Killer in ready-to-use, concentrate and ready-to-spray liquids kills and controls common rose pests and hundreds of other garden pests, including ants and other nuisance pests attracted by honeydew. Tough on aphids and beetles, but gentle on gardens, these highly effective insecticides keep on working to protect your roses for up to three months. Sevin ® Insect Killer Granules even takes control over lawn grubs from rose pests, too.
With trusted products from the Sevin ® brand line of insecticides, you can feel confident about handling rose pests and pest control — and get back to watching your roses fulfill their potential. GardenTech ® brands and the GardenTech blog are here to help you grow and enjoy beautiful roses and healthy, productive gardens.
The Tree Center
How To Get Rid Of Aphids
If there’s one class of insect that bothers gardeners more than any other, it has to be aphids. These tiny pests can be found worldwide and they are to plants what mosquitoes are to people – small but destructive vampires. Aphids feed on the sap of plants, which is damaging enough on its own, but to get to the sap they chew up the leaves with their efficient jaws. They also breed rapidly and won’t stop feeding until they kill the plant, at which point they migrate to the next plant and the cycle starts all over again. To a biologist aphids are actually fascinating – some species of ants farm them, for example – but to gardeners they’re a serious pest.
Luckily aphids aren’t that hard to get rid of, but you do need to act quickly at the first sign of a problem. Otherwise the speed they reproduce at will overwhelm the affected plant, and even if it survives the damage can be serious. Almost no plant is safe from them; there are more than 4,400 known aphid species, about 250 of them classed as serious pests. They vary in size from a millimeter to almost half an inch and can be a wide variety of colors. Most common are green, black and white. They generally have soft, pear-shaped bodies with a prominent tube protecting from the rear. Some of them can be mistaken for other insects but the damage they cause is quite distinctive.
The leaves of an aphid-infested plant will start to turn yellow and curl inwards, and new shoots are often deformed. Another thing aphids do is secrete a sticky substance called honeydew. Ants love this, which is why they sometimes farm aphids – they “milk” the tiny insects to make them release it – but when it collects on a plant it often attracts fungus spores and causes a black infection that’s often lethal. Aphids can also carry plant diseases in their bodies, and if they suck sap from a plant that’s infected with a virus then move to a healthy one they usually infect it too. Basically they’re a nuisance and they need to go.
Preventing Aphids From Colonizing
The first thing you can do is try to prevent them colonizing your garden in the first place. This isn’t easy. Aphids are usually wingless, but some species will have winged offspring in summer or if food runs low. That means they can get around, so no defense is foolproof. You can improve the odds, though.
Any time you bring in a new plant check it carefully before you take it anywhere near your garden. Look for feeding aphids, and also check underneath the leaves for egg clusters. Aphid eggs are tiny, but they lay them in bunches so they should be visible as small white flecks. If the plant turns out to be heavily infested it’s best to get rid of it. A few aphids can be dealt with, but you need to be thorough or the result could be disaster for your whole garden. If you have any doubts at all treat the plant before introducing it.
Another way to deter the little pests is to avoid over-fertilizing. Too much fertilizer can encourage very rapid plant growth, and that means lots of fresh green shoots – aphids’ favorite food. Use slow release fertilizers; that should keep growth rates normal, and prevent your yard becoming a favorite aphid spot.
How Aphids Interact with Other Insects
Think about other insects – aphids can have complicated relations with them. Ants are often beneficial but if you see them carrying aphids around they need to go too. The idea of ants farming is quite impressive, but not if they’re using your plants as fields to grow aphids on. The species that do this will protect their aphids from predators and carry them from infested plants to healthy ones, to give themselves a nice crop of honeydew, so you can’t have them around.
Ladybird beetles, however, are a completely different story. They look cute but they’re voracious predators, and they love snacking on aphids and scale. If you see them around your plants leave them alone – they’re very efficient at pest control. You can encourage them to settle and breed by getting a ladybug house. If you’re really in a hurry you can buy a tub of a thousand live ladybirds online for less than $10. If you have wrens in the area try setting up some small nesting boxes – these little birds also eat aphids (although they might eat the ladybirds too).
Getting Rid of Aphids
Check your plants every few days in summer, looking out for either aphids or egg clusters. If you find any, act right away. A single aphid can have up to 80 offspring in a week, and it often does only take a single one – many aphids can lay eggs without mating. If you find any, the first thing to try is just washing them off. A high-pressure hose attachment like a Bug Blaster will knock them off, and usually they won’t be able to get back onto the plant – they aren’t very mobile once they’re on the ground.
Alternatively you can mix two teaspoons of dish soap into a pit of lukewarm water and spray the infected plants with it. Soap suffocates aphids by clogging the pores they breathe through. If you don’t fancy using dish soap you can also buy special insecticidal soap. It can take several applications to cure the problem, and it’s best to spray neighboring plants as well. Make sure to soak the undersides of the leaves – miss those areas and newly hatched aphids will be munching away within days.
In extreme cases insecticide powder or spray might be needed, but these can be hazardous to children and pets, and you don’t want to use them on vegetable crops if you can avoid it. Soap works as well as nearly anything. If one of your plants has a really bad case you can prune away the worst affected parts – sometimes you might need to sacrifice the whole plant, if it’s already sickly and has a very heavy infestation.
Aphids are some of the most destructive insects you can find, but regular checks and some simple treatments will keep them under control. The trick is to not leave them undisturbed – if you do that your garden will quickly be overrun and badly harmed. Be vigilant for the tiny pests, and take action right away if you find them. Infestations are very common but you don’t need to let it ruin all your hard work.
Comments 24 comments
Very informative. Please advise how much water to use with 2 teaspoons of dish soap to spray the aphids.
Many thanks, Diane Naude
One pint of water …. the “n” was dropped.
We have very old elm trees. They are infested with aphids. How can we get rid of them. They ruin summer with the raining of their sap better known as poop. HELP.
Tina, I share your pain and my aphid-infested elm trees are what landed me searching Google yet again and here on this post. It’s so discouraging, none of the advice I find seems to apply to trees. And my front yard is nearly unusable during the best months in the PNW. Not to mention our car! Yuck. But the trees are old and beautiful. These aphids were established when we purchased our house three years ago. What a mess.
Jessica, I had the same problem. At first I didn’t know where that stuff on my car was coming from. It became intolerable and I was having to park my car in the garage. After doing some research, I bought the compare and save systemic tree and shrub insect drench. I got it on Amazon. I followed the directions last week. For days I could just see lots of drips coming out of the tree. Tonight I’m watching and watching and don’t see anything yet. I really don’t think it works that fast, but it’s done something! I would give it a try.
Use a product called Acecap. They are tree implants. You can buy them on Amazon.
After researching the same problem, I ordered Compare-N-Save Systemic Tree and Shrub Insect Drench. I used 9-10 ounces per tree as they are all about 20 inches in diameter and about 20 feet tall. (I called the product support line to clarify directions). It was a lot of work to clear the area around these trees – 15 of them and all located on a bit of a hill. It takes a little bit of time for the product to dissolve in the water and then about 15 minutes per tree to get it to soak in without run off. In a few days, I am going to use soapy water spray to the trees to get the bug residue (aphids and mealey bugs) off the branches and then apply Neem oil. Product support tech told me to expect it to take about a few weeks to two months to see results. I am hopeful just to save these badly infested trees.
Hi. I have 3 trees infested with aphids and it seems like it happens every year only on these particular trees although there are many other and different trees around them. I’m thinking the problem is in the tree itself, happens every summer, nothing in the beginning but later in June and throughout the summer they become so full of aphids and leaves look like they are sprayed with shiney overcoat material. Also you can see the mist of honeydew falling from the tree, my cars parked in the driveway next to them are full of that material which now is attracting a lot of wasps and tarantula hawks. What do you suggest I do? Thank you
Well this is the first I ever heard of them . My drive way/cars and front yard is a sticky mess. This is the first year we have ever seen an issue we noticed leaves falling more than usual and then the sticky honey dew right after. Unbelievable how bad it has gotten. Now that I know what it is I am going to try trimming out tree and get the hose and soap out or maybe even the power washer and hopefully get these crazy little bugs away. I wish you guys luck . Wish me luck too
look at Guy’s comment above. I believe that is the only solution that will work. Acecap it is!
We have the same issue with the tree in our front yard. We just bought this house and nobody wants to park in the driveway. We will be trimming the leaves way back and try a soap solution. But if they continue we will cut the tree down. And hopefully chose one that aphids don’t like.
I have a large tulip tree and the honeydew is driving me mad, how to I get rid of them in a tree.
My tree is infested with aphids and now thornets, wasps and bees that are feeding on the aphids as well! Any suggestions on how to get rid of all of them safely? I am afraid to spray the tree at this point due to all of the commotion on the tree. This happens every year and it is a safety issue.
A neighbors willow tree is ruining my life. Far away from their house but directly on our property line I am dealing with a severe aphid infestation. We cannot be in the yard. As well as it appears the nymph must blow in the wind and land on my car. I don’t know what to do about it. I bought a spray just to do some knockdown and did my lawn and the fence where I could see them. But now they are back in record numbers. Safe soap will kill if directly applied but we are talking about a willow hundreds of feet tall. Besides all the b.s. of limbs and leaves 365 days a year, NOW THIS! I googled today and found out the eggs can survive frost. I am at wits end.
I have a hibiscus that is between 25-30 yrs old and is infested yet again. I cut it back to the bare bark.. sprayed it with soap mixture.. cleaned all dropped leave and debris from around it.
It started growing, I watched it closely, it seemed fine. So I let it be other than fertilizer and water, it’s completely filled out and started blooming again, then last week I notice the blooms dropping and low and behold, completely covered in aphids.
It’s so bad I just want to burn it down but because it’s one of the earlier breeds, I can bring myself to do it.
It’s way to full to do each leaf with any soap solution. I’m so bummed.
Idk what I’m going to do at this point!
I have a willow tree that has wasps drawn to it and goggled why low and behold it was because of those pesky aphids. How do I save my tree I just planted it 3 years ago and there is already a black fungus around the bottom of the trunk ?
I tried everything even gone to home Depot and bought the strongest stuff noting works to kill the Aphids, any advice please. Email: [email protected] thanks.
they are little pest like any of them ,ley eat all the leaves on my pink rose i sprayed and then cut them back and have them hanging on my chair.or well seewhat happenes.
My crepe myrtles were attacked. I sprayed with neem oil and it did not help. What helped was spraying with water, basically washing the leaves, removing the black soot.
Can anyone tell me, please? Am I cutting my tree down if it’s totally infested, or do they go away and come back next year, or…what do I do?
if I destroy the tree will the aphids stay on the property and go to all the other trees and shrubs?
Last year I finally found out what was drawing all the bees to our big tree out front, and our mailbox. And why all the sticky stuff on driveway. Aphids. I purchased one of those bottles with spray nozzle for hose. I put dish detergent and water in it and sprayed away. A lot. Sprayer reached almost to the tippy top, it was powerful. I will do it again this year as precaution.
I cleaned mailbox as well.
I have to say, while I was spraying the tree I noticed all the gooky sap dripping off the tree. It was gross. Yuck So much sap.
What about a pkg or 2 of lady bugs? Aren’t they affective?
I have a very large oak tree full of aphids. They die off in the winter and always seem to come back in the spring/summer. They leave this horrible black droppings, all over my driveway and have killed my Crepe Myrtle and other folige. The tree is to large to treat. What should I do?