Aphids often appear out of nowhere in spring and attack the young leaves and shoots of many plants with their piercing-sucking mouthparts. Here are some home remedies that can help against aphid infestation.
Aphids: appearance, pests and what helps against them
Aphids make life difficult for many gardeners every year anew, because they are among the most common plant pests. Within a very short time, the yellow, green, reddish or black insects can grow into huge colonies and damage the leaves and young shoot tips of many plants with their piercing-sucking mouthparts. In addition, aphids often transmit dangerous pathogens, especially viruses, when they suck. Therefore, you should not take an infestation lightly, especially with fruit trees.
But you do not need to immediately resort to the “chemical mace”. There are many inexpensive and biologically produced home remedies that have proven effective in combating aphids. If individual plants are infested, it is often sufficient to spray off the pests with a sharp jet of water or to wipe them off with the fingers. Since flightless aphids are not very mobile, the chance of a new infestation is very low.
In the case of a more severe infestation, homemade broths, decoctions and teas made from various wild plants, which are particularly rich in certain minerals, are particularly suitable. Used regularly, they are not only effective against various plant diseases and pests, but often also provide the plants with additional important minerals.
Appearance: How to recognize aphids
There are various species of aphids all over the world. About 800 of them are also found in Central Europe and make life difficult for gardeners. What an aphid is called can already provide valuable clues as to its preferred host range.
If you have discovered a possible infestation, subject the aphids to species identification. This way, you will know exactly where the pest likes to reside. Visually, aphids are very variable. They grow to about one to two millimeters in size and appear in a wide variety of colors. Thus, black aphids can occur just as red, yellow, green, brown or white aphids. Even flying aphids appear in our gardens.
The insects can also be recognized by the fact that they like to appear in colonies on plants. In doing so, they sit densely packed on the shoots, which makes identification all the easier.
Mode of life of aphids
This aphid, like slugs, is one of the most common pests in the garden. So it’s good if you study their habits in advance and understand how aphids behave when reproducing.
Usually, the main season of the aphid begins in the spring and ends in the fall. Especially the first months, when it is slowly getting warmer, are valuable for this pest, which is why infestations are more frequent here. This is due to the fact that aphids lay eggs that overwinter in the garden. The remarkable thing is that it doesn’t take more eggs than this to create huge colonies.
Aphid reproduction, in fact, occurs by parthenogenesis. This means that females can clone without laying any eggs at all. In good conditions, a female manages to generate five new insects per day. Development then takes around two weeks. And even though the tiny insects only live for a few weeks, they still produce many offspring.
The will to survive of the pests is truly impressive: it is even possible for them to mutate. An animal without wings can therefore produce winged offspring. The environment determines possible adaptations. And if the pest can fly, new plants are quickly affected.
Damage pattern and consequences of infestation by aphids
Infestation with aphids is often similar: within a short time, whole colonies of small animals get onto fresh and new shoots of many plant species, bite them and feed on the plant sap. The damage itself is usually not too bad for the plant, however, secondary symptoms such as black spot on the colonized leaves lead to leaf loss in the long term.
Black spot can develop because aphids excrete honeydew. Sugar that is not used lands on the leaves and forms a sticky film on which fungi feel at home. Another problem with infestation is the possible transmission of viruses. For example, tobacco mosaic virus or plum pox virus can cause unpleasant secondary damage.
In general, aphids cause a pattern of damage that can be very diverse. Clear indications are also:
- Colonies on leaf undersides and shoot
- Scanty growth
- Curling of the leaves
- Discoloration of the leaves
- Dried up leaves
- Leaf drop
Which plants do aphids prefer to infest
Since there are many aphid genera, the host spectrum is also quite broad. Aphids are particularly common on
- Garden jasmine
- Swiss chard
- Angel’s trumpet
- Red currants
- Guelder rose
- Chili plants
Even in the kitchen garden, the aphid is not uncommon. The green lettuce aphid (Nasonovia ribisnigri) likes lettuce, the black bean aphid (Aphis fabae) likes beans, and the carrot aphid (Dysaphis crataegi), in turn, likes to sit at the base of carrot greens. Other victims of various aphids are strawberries, raspberries and even apple tree and cherry tree.
Equally unpleasant is the green peach aphid (Myzus persicae), which lives mainly on peach trees during spring and later seeks new hosts. At the same time, it appreciates vegetable crops, which is why peppers and zucchini may also have aphids. Cucumbers are also not safe from the pest. Aphids on cucumber plants often belong to the genus of green cucumber aphid (Aphis gossypii).
But that’s not all: the green pea aphid (Acyrthosiphon pisum) attacks pea plants. Surprisingly, these are often red aphids. Last but not least, the mealy cabbage aphid (Brevicoryne brassicae) can be found in the garden, especially on cauliflower.
A strong attracting effect on the aphids has green color. This is important to know when it comes to preferred plants. Thus, aphids like
Furthermore, aphids are more common on houseplants and in ornamental gardens. For example, oleander can have aphids, but they can also be found on
- Guelder rose
- Garden jasmine
In the garden, it may be helpful to cultivate red-leaved varieties instead of green lettuces. Here, the attracting effect is omitted. Furthermore, there are various plants that have a certain tolerance or resistance.
Preventing aphids: what you can do
Preventive help against aphids is valuable. As a general rule, weakened plants are more susceptible to disease and pest infestation. Especially for ornamental shrubs with lush blooms such as hibiscus, garden jasmine, as well as roses, sufficient supply and care is essential, as a lot of energy is invested in the enormous flowering splendor, which can quickly lead to deficiency symptoms.
We show eight measures to prevent aphids:
Clean stems thoroughly
Towards the end of the season, the pests place their eggs well hidden on woody plants. Especially tree bark is a favorite place. Therefore, brush the trunks thoroughly before painting them white. In this way, you remove both eggs and overwintering specimens.
Spray with vegetable oil in winter
Use preparations containing vegetable oil as a preventative against aphids in winter. The oil lays like a film on the overwintering eggs and cuts off the oxygen supply. Thus, the next generation dies.
Strong plants have more to resist pests. Therefore, fertilize carefully and professionally. It is essential to refrain from applying too much nitrogen, as this can soften the plant tissue, making the sap more easily accessible. When fertilizing, you should take into account the individual needs of the plants, the PH value of the soil and the appropriate timing and dosage.
Create mixed cultures
Which plants don’t like aphids? This question is important when it comes to driving away and deterring aphids. In mixed cultures, you can take advantage of the deterrent effect of some plants, such as.
Naturally, the plants act against aphids and can thus prevent infestation.
Apart from this, mixed crops are also very important for plant health. Aphids in raised beds are more common when there is too little variety. With deterrent plants in the mixed culture, you prevent the aphid from spilling over to other plants. Also, make sure host plants are widely spaced and do not place rows with the main wind direction. This will prevent the animals from reaching other plants with the airflow.
Choose optimal location
A proven remedy against the pests is already the choice of the location of your plants. The more comfortable a plant feels in your garden, the more resistant it is. Consequently, make sure that its needs are met in terms of light, pH and soil conditions. Soil improvement measures are also advisable.
Increase humidity around plants for protection. Aphids are also less likely to infest orchids indoors if you spray them regularly with water.
Keep them tidy
For hibernation, aphids use not only tree trunks, but also dead plant parts as well as woody plants. Therefore, you should remove eggs and aphids by thoroughly removing crop residues and generously pruning back plants in the spring.
Use horsetail extract as a preventive measure.
The silica contained in horsetail extract is a popular tonic for plants. If you spray endangered plants with it once a week, it will be difficult for the troublemakers to get hold of the sap.
Control aphids naturally with beneficial insects
Like many other pests, aphids have natural enemies. Provide a home for them and install beneficial insect houses and insect hotels in your garden. If you want to control aphids, these beneficial insects will help:
Ladybugs and their larvae
It is recommended to use ladybugs against aphids, as this is one of their most effective predators. The control is even better if you place ladybug larvae. These eat per day up to 800 of the small aphids, while adults come to 150 per day.
If ladybugs are to be used against aphids, you must first do something against ants in your garden. Otherwise, these could counteract the control measure.
Attracting earwigs is also worthwhile if you want to control aphids naturally. If you place flower pots filled with wood wool with the opening facing down near affected plants, earwigs will thank you by eating the pesky pests.
Green lacewing larvae
Starting at a temperature of around 12 °C
/ 54 °F, lacewing larvae can be used as beneficial insects against aphids. Especially if you have aphids in the greenhouse, this measure is advisable, because the larvae do well in this environment. Once they are fully grown, the lacewings fly outdoors and need to be replaced.
The beauty of lacewing larvae is that they are predators not only for aphids, but also exterminate thrips, mealybugs and spider mites.
If ichneumon wasps are to help against aphids, they must belong to the genera Aphidius colemani or Aphidius ervi and be used at temperatures above 15 °C
/ 59 °F. Females parasitize the pests by laying their eggs directly inside. After about two weeks, the adult hatchling wasp hatches and can again combat the pest. One wasp is sufficient to destroy about 200 aphids.
You eliminate aphids on permanent crops in the greenhouse particularly effectively with the gall midge. The greenhouse is a good place because the beneficial insects like it bright and humid. You apply the pupae in an uncomplicated way. They are considered particularly effective against green aphids that like to sit on cucumbers.
Beneficial insects are excellent natural remedies against aphids. Therefore, you would do well to design your garden as close to nature as possible. By creating deadwood corners and a species-rich range of flowering plants, you can ensure optimal conditions for a stable population.
Fighting aphids: The best home remedies
Once the pest has established itself, you should fight aphids. However, you do not have to resort to the chemical mace, as there are many good home remedies against aphids, the use of which is easily successful.
You can use garlic against aphids in different ways. In the case of a light infestation, it is enough to stick a clove in a peeled state halfway into the soil near the stem of the plant. The animals do not tolerate the oils it contains. If the infestation has already intensified, spray the plant with garlic broth.
Recipe for garlic broth
Put three peeled and diced garlic cloves in a sealable container and fill it with a liter of water. Then the decoction must infuse for about two weeks. With a spray bottle you now wet the plant generously and should treat especially the undersides of the leaves and the stalks.
Oregano against aphids also shows its effect in the form of a broth. To do this, mix about ten grams of the dried herb with a liter of boiled water. After cooling, filter the decoction and dilute it with water in a ratio of 1:3. Spray this mixture thoroughly on the plant.
If you want to use milk to fight aphids, mix it with water in a 1:2 ratio and spray it on the plant. But why does milk kill aphids? The reason for this effect is the lactic acid it contains. It attacks the body of the pests and thus leads to their death.
Potash soap suds
Potash soap is a kind of soft soap that helps against aphids. To make it work, you first need to prepare a soap solution and spray it on the affected areas. The soap contains linseed oil as well as potassium hydroxide, which together have an antiparasitic effect. However, it does not harm larger insects.
Caution: sensitive plants with fine foliage can be damaged by treatment with soap suds against aphids. Therefore, test the agent in advance on a small area for tolerance.
Recipe for potash soap suds
Prepare a natural remedy against aphids from 20 grams of the soap and a liter of lukewarm water. The mixture must be stirred to dissolve the soap and then immediately ready for application.
The best remedy for aphids on roses is considered to be onion broth. It kills the pests and proves to be pleasantly gentle on the plant. After preparing the broth, spray it on the plant over a wide area and not too sparingly, wetting especially the coveted hiding places of aphids.
Recipe for onion broth
First, cut a Spanish onion into cubes and boil them well with about a liter of water. Immediately after the water begins to boil, set the lowest temperature and give the broth about 30 minutes. Gently simmering will release the valuable substances from the onion. Once the broth has cooled, remove the onion pieces and use the liquid undiluted.
Both the fragrances and other substances from nettles counteract the plague. Nettle liquid manure or nettle decoction against aphids is suitable for use on ornamental as well as crop plants. You can use it to combat aphids on tomatoes as well as on oleander or snowball.
Recipe for nettle decoction
Pick about half a bucket full of fresh nettle leaves and pour fresh water over them. The decoction must now rest for about 48 hours in a shady and not too warm place. To avoid contamination, protect the opening with a net. After pulling, the liquid is separated from the leaves and continue to use undiluted. Nettle against aphids is best sprayed over the entire surface.
Field horsetail liquid manure
To make a field horsetail liquid manure, you will need one kilogram of fresh or 200 grams of dried herb soaked in ten liters of cold water for 24 hours. Dilute two liters of the liquid manure with ten liters of water and water or spray your plants with it weekly. Caution: Field horsetail liquid manure is only effective against aphids in the early stages or as a preventive measure.
As a proven home remedy anyway, black tea also helps against aphids. The tannins it contains quickly cost the pests their lives. All you need to do is boil two tea bags in half a liter of water and let it sit for about a quarter of an hour. After it cools, spray it on the plant. Black tea kills the aphids, but it does not harm plants. Therefore, you can treat more sensitive plants with it as well.
A wormwood tea helps not only against aphids, but also against various sucking and eating pests. For the tea, 100 grams of fresh or ten grams of dried wormwood leaves (Artemisia absinthium) are brewed with a liter of boiling water and strained through a fine sieve after 24 hours. You can use the tea undiluted against aphids in spring and summer.
Canola oil mixture
A proven remedy against aphids is canola oil. The oil works in two ways: on the one hand, it makes the pests lose their grip, and on the other hand, it covers their breathing holes and suffocates them. However, you should not use pure rapeseed oil against aphids.
Caution: Fighting aphids with canola oil works well, but not all plants tolerate it. Especially sensitive specimens should therefore first be wetted with the agent in a small area for testing. Wait before further treatment to see if any damage appears.
Recipe for rapeseed oil mixture
To five liters of fresh and cold tap water, add about 90 milliliters of canola oil for this home remedy against aphids. To facilitate emulsification, also add a little dishwashing liquid and stir vigorously. Then apply the mixture with a plant sprayer. Repeat after about a week if you have not caught all the aphids with the canola oil recipe.
Cooking potatoes usually produces cooking water. This is better not to pour away, because with it you can fight aphids biologically. Especially in the greenhouse, this measure is recommended when the infestation is not yet too strong. Plants are sprayed with the water all around, repeat after a few days without risk.
Rhubarb leaf broth
If the black bean aphid has spread in your garden, rhubarb leaf broth will help. Spray the ready-made broth on the affected plants once a week and check its success thoroughly in between.
Recipe for rhubarb leaf broth
Boil half a kilogram of rhubarb leaves in three liters of water and simmer the mixture for about half an hour. Subsequently, separate the leaves from the liquid and spray it on the infested plants after cooling.
These home remedies against aphids are ineffective
A wormwood liquid manure, unlike wormwood tea, does not kill the pests, but only confuses them with its strong and pungent smell. Vinegar also does not kill aphids directly, but only prevents infestation, as the parasites shy away from acid. In addition, you have to be very careful with the dosage, because the strong acid also attacks the leaves if the concentration is too high. A nettle liquid manure has a stimulating effect on young plants as a watering treatment. It also strengthens weakened plants, but does not help in the fight against pests already present
Other things to do against aphids
Rinse off and collect
The tiny insects can only cling to plants to a limited extent. They can be easily removed with a jet of water. After treatment, collect the small animals and dispose of them in the household garbage. You can use this method to get rid of aphids if you have a small infestation.
Dispose of shoot tips
Since aphids like to stay on shoots and leaves that are still young, you can cut them off to control them. Then dispose of the cuttings in the household waste.
Shower off houseplants
Aphids on houseplants can be easily washed off if the infestation is low. To do this, protect the soil and the pot with a plastic bag and bring the plant into a horizontal position. Then shower the leaves with a not too hard water jet so that the aphids fall off the houseplant. If the following day there are still pests on the plant, it can simply be showered again.
Common questions about aphids
Aphid is such a common pest that sooner or later every gardener makes acquaintance with it. This raises some important questions, which include not only “What helps against aphids?”.
Why do ants protect aphids?
Ants and aphids share a delicious relationship. Ants appreciate their sweet excretions, so they protect them against predators such as ladybugs. Ants rarely eat aphids, however, because they don’t want their food source to dry up. Therefore, they milk the aphids instead, thus preserving them.
Do wasps eat aphids?
Yes! Even though wasps are not always popular in the garden, they prove to be a real help in the fight against the pests. Keep this in mind when a wasp appears as an uninvited guest at your next barbecue party and you want to get rid of it.
Can aphids fly?
Some species and specimens are able to. They often develop wings when environmental conditions dictate. This is made possible by mutations that occur during cloning.
Are aphids dangerous in lettuce?
No! Of course, you should wash any lettuce thoroughly before eating it. However, if an aphid does get stuck on it and you eat it, this does not pose a health risk.
Do aphids infest humans?
No! Humans are unsuitable hosts for aphids and are therefore completely unattractive.
Do caterpillars eat aphids?
No! Caterpillars are herbivores. However, there are some larvae of other insects that resemble caterpillars in appearance and like to feast on the aphids.