Tomato pests: fight aphids & Co. naturally

Black lice and flies on tomato plants indicate a pest infestation. We introduce the most common tomato pests and show how aphids, fungus gnats and the like can be combated naturally on tomatoes.

Tomatoes are very popular not only with many gardeners, but unfortunately also with some pests. We will show you which pests often attack tomatoes and how you can get rid of them efficiently and naturally.

Fight tomato pests

A number of pests can attack tomatoes. Not only can the plant be weakened, but the fruits can also quickly look unattractive or lose their quality. It is therefore important to discover the pest as quickly as possible and to determine which culprit it is.

Aphids on tomatoes

As soon as the tomato plant takes shape in early summer, the first are often already Aphids (Aphidoidea) to see. The insects, which are only a few millimeters in size and are usually green or black, can be found mainly on the tips of the shoots. The little pests prick the phloem, certain channels in the plant, and suck on the sugary plant sap. This weakens the plant and leaves are often deformed due to the sucking activity and saliva of the lice. Another sign that tomatoes have been attacked by lice are shiny spots or coatings on leaves. This is honeydew, sugary excretions from aphids. Black fungi can form on these deposits, which are also easily recognizable when the infestation is advanced. These fungi hinder photosynthesis and thereby weaken the plant even more. Ants are also interested in honeydew, which is why an increased occurrence of ants on a tomato plant can be an indication of an aphid infestation. In addition, the aphids can transfer viruses from one plant to the other and thus damage the tomato plant.

tip: Aphids multiply rapidly. The number can increase by a factor of about 10 per week. If you recognize an infestation, you should act promptly to avoid a mass increase.

Fight aphids on tomatoes

In the event of a slight attack on tomatoes by aphids, home remedies can be used. Soap suds or nettle broths are suitable for this, as we show you in our special article Home remedies for aphids describe in detail. If you don't want to bother with preparing a home remedy or if the infestation is more severe, we recommend an organic pesticide. Synthetic agents pose a strong risk to beneficial insects, which is why we advise against these agents.
Biological agents based on neem oil are particularly effective. This oil from the seeds of the neem tree allows you to get rid of aphids naturally. Our Plantura organic pest-free neem is based on this effective neem tree oil. The agent is purely herbal and can be used both outdoors and when growing tomatoes in a greenhouse. The active ingredient is absorbed by the plant and enables you to catch aphids sitting hidden. The quick suction stop prevents further damage. At the same time is ours Organic pest-free neem not dangerous for bees.

To treat an area of ​​ten square meters with tomatoes, just mix two milliliters Organic pest-free neem with 600 milliliters of water. You can then spray this emulsion onto the infected plants. After treating your tomatoes with organic pest-free neem, there is a waiting period of three days, during which you do not harvest and consume any fruit. After this time, the active ingredient is broken down to such an extent that you can consume the fruit with pleasure. Please use our organic pest-free neem according to the specifications in the application recommendation. You should read the instruction leaflet carefully before use.

In addition, other biological agents based on rapeseed oil are commercially available. Unfortunately, due to their lower effectiveness, these have to be applied more frequently, which is harmful to some plants. Another possibility is the use of beneficial insects. Parasitic wasps, lacewings or ladybird larvae can be used against aphids. The use is particularly effective in a greenhouse or similar closed room. Please note, however, that beneficial insects cannot be used in combination with pesticides.

As a preventive measure, you can encourage beneficial insects in your garden with a natural garden design, for example with a flower meadow that is as pristine as possible. Our Plantura beneficial insect magnet is a seed mixture that enables you to create such a flower meadow. You should also ensure a good supply of potassium and reduced nitrogen fertilization when fertilizing your tomatoes. This makes your tomatoes less susceptible to aphids. We recommend that you use special tomato fertilizers that are tailored to the needs of your tomatoes, such as ours Plantura organic tomato fertilizer.

More tips like you Fight aphids naturally we have put together for you in our special article.

Summary: fighting and preventing aphids on tomatoes

• Home remedies such as soapy water or nettle stock are possible in the case of slight infestation
• Biological pesticides like ours Plantura organic pest-free neem or means based on rapeseed oil
• Beneficial organisms such as parasitic wasps and ladybird larvae, especially in protected cultivation
• Promote beneficial organisms in the garden as a preventive measure
• Make plants more resilient through needs-based fertilization

Black flies on tomatoes

Do you often see small black flies on the potting soil of your tomatoes? Then it is most likely to be fungus gnats (Sciaridae). If there are only small flies on the leaves of your tomatoes, it is certainly an infestation by thrips (Thysanoptera). In the following we will show you how you can fight fungus gnats or thrips on tomatoes.

Fighting fungus gnats on tomatoes

The best way to recognize an infestation of your tomatoes by sciarid gnats is the staggering black, adult flies. In order to recognize an infestation as early as possible, you can Yellow panels insert. These are coated with glue and attract the sciarid gnats. The insects stick to the boards and allow you to recognize an infestation at an early stage. Yellow panels can also be used preventively, but in the event of a real infestation they are not sufficient to combat it.

The larvae of the black flies live in the potting soil and feed on organic material, including the roots of tomatoes. This can harm your plants and lead to withered leaves and poor growth in the long term.

If you recognize the infestation early on, you can use a home remedy. In our special article on the topic Fight fungus gnats with home remedies, we will show you how you can get rid of flies with garlic, for example. In Germany, no chemical or natural sprays for the treatment of fungus gnats on tomatoes are currently approved. If the infestation is advanced or if it does not work, we recommend that you act quickly and, for example, use beneficial insects. The predatory nematodes Steinernema feltiae for example can be used specifically against an infestation by sciarid gnats. The success is visible after a few days. Another beneficial insect against fungus gnats is the predatory mite Macrocheles robustulusthat can be used in protected cultivation. If the infestation is severe, it can also be helpful to repot the plant and wash the root ball with water. This is how you get rid of a large part of the infested earth. Then the plant is repotted.

Sciarid gnats only feel at home in permanently moist soil. We therefore recommend that you avoid waterlogging as a preventive measure. It is also very effective to spread a 0.5 centimeter thick layer of sand, grit or expanded clay on the potting soil to keep the surface dry, which also helps preventively. This is the best way to directly protect all potted plants in the vicinity.

Summary: fighting and preventing fungus gnats on tomatoes

• Yellow panels to identify an infestation at an early stage
• If the infestation is mild: use home remedies such as garlic
• No chemical or natural pesticides allowed against fungus gnats on tomatoes
• Beneficial organisms such as the predatory nematode Steinernema feltiae or the predatory mite Macrocheles robustulus work very well when used correctly
• If the infestation is severe, repot the plant and remove the old soil if possible
• As a preventive measure, avoid permanently damp earth and apply a thin layer of sand to the earth - also protect other plants in the vicinity in this way

Fight thrips on tomatoes

Thrips (Thysanoptera) feel particularly comfortable in low humidity and constant temperature - for example in living rooms. The insects themselves are so small that they can hardly be seen with the naked eye. An infestation can be recognized primarily by the typical damage pattern: Small yellow or silvery-gray speckles on leaves or flowers. If the infestation is more severe, these dots can become larger and the infested leaf can die. Besides, you can Blue boards place near the potentially infested plants. The color of these boards attracts the thrips, which stick to the glue. In this way you can identify an infestation at an early stage.

Soapy water with olive oil or leaving the houseplants out in the rain are smart home remedies that can help with a light infestation. More about home remedies for thrips and how to use them Fight thrips successfully can be found in our special article.

Beneficial animals can also be used as a biological method. The most effective is the use of the predatory mite (Amblyseius cucumeris) or the lacewing (Chrysoperla carnea) in the greenhouse. If it is unsuccessful or if mixing up a home remedy is too time-consuming, we recommend an organic pesticide. Agents based on neem oil are particularly effective in the event of an attack by thrips. Our Plantura organic pest-free neem is also based on this highly effective oil and was already presented above in connection with aphids.

As a preventive measure, we recommend that you ensure that the air humidity in rooms or in your greenhouse is kept stable and that it does not drop too much.

Summary: Combating and preventing thrips on tomatoes

• In the case of a slight infestation: household remedies such as soapy water with olive oil
• Beneficial organisms such as the predatory mite (Amblyseius cucumeris) or the lacewing (Chrysoperla carnea) in the greenhouse
• Biological remedies based on neem oil, like ours Plantura organic pest-free neem
• Avoid very low humidity as a preventive measure
• Blue boards for early detection of the infestation

Whiteflies on tomatoes

A whitefly is the name given to different genera and species of whitefly (Aleyrodoidea). Especially the cabbage moth scale (Aleurodes proletella) and the greenhouse whitefly (Trialeurodes vaporariorum) cause an annoying infestation here on land. This can be recognized by the small white insects on the underside of the leaf. Small white eggs, often deposited in a ring, can also be discovered there. When the plant is touched, the adult insects usually fly away in a small arc.

Fighting whiteflies on tomatoes

A nettle stock is particularly suitable as a home remedy for a slight infestation. You can also use soapy water made from potash soap and treat the plant with it. If the infestation is more severe or if the home remedy does not work satisfactorily, we recommend using an organic pesticide quickly. Our Plantura organic pest-free neem, which you already got to know above in connection with aphids on tomatoes, can also be used effectively against whiteflies on tomatoes.

Other biological agents based on orange or rapeseed oil are also available. These agents work on contact, as they block the oxygen supply to the insects and so they die. You can also buy products made from potash soap ready-mixed. In addition to these biological agents, you will also find agents based on acetamiprid and deltamethrin im Trade, but both are too harmful for beneficial insects and the environment, so we do not recommend them can.

Another possibility are beneficial insects that can be used against the whitefly. These include different species of parasitic wasps (Encarsia formosa), the predatory bug (Macrolophus pygmaeus) and predatory mites (Amblyseius swirskii). Such targeted use in closed spaces, such as in a greenhouse, is particularly effective. You should make sure that you do not use beneficial insects in combination with a pesticide.

The whitefly can easily survive in the greenhouse even in cold winters. That is why prevention in the form of good hygiene in the greenhouse is important. Infested plants should not be dragged in, or infested plants should be isolated immediately. The whitefly does not take in a constant draft very well - another reason why you should always ensure good ventilation in greenhouses.

Full details on how to Fight whiteflies naturally we will show you in our special article.

Summary: Controlling and preventing whitefly

• In the case of a slight infestation: home remedies such as nettle stock
• Especially with more severe infestation: biological agents like ours Plantura organic pest-free neem
• Beneficial organisms such as parasitic wasps, predatory bugs and predatory mites are particularly possible in protected cultivation
• As a preventive measure in the greenhouse, make sure not to put any infested plants in it
• Make sure there is good ventilation in the greenhouse

Spider mites on tomatoes

Spider mites (Tetranychidae) occur especially when growing in a greenhouse. Chilli and bell peppers are particularly prone to infestation that can quickly spread to tomatoes. Spider mite infestation on tomatoes can mainly be seen in the webs of the little eight-legged creatures. These very fine webs can usually be recognized by their branches or leaf styles. If the infestation is advanced, characteristic, point-like lightening can be seen on the leaves.

Fight spider mites on tomatoes

There are many effective home remedies against spider mites: In the event of a slight infestation, you can remove infected parts of plants from pruning-compatible plants. By hosing the plant daily with a gentle stream of water, you increase the humidity for the spider mites, which will help get rid of them. You can increase this effect by putting a clear plastic bag over the plant. To prevent damage to the plant, we recommend doing this for a maximum of four days. We strongly advise against the use of a tobacco brew that is mentioned again and again in various guidebooks. Nicotine is a neurotoxin that is toxic to humans and its use on plants has been a criminal offense in the EU since 2001.

The use of gall mosquitoes (Cecidomyiidae) or predatory mites (Gamasina) is one way of declaring war on spider mites with beneficial insects. Especially the predatory mites Phytoseiulus persimilis or Amblyseius californicus can be purchased on the Internet and used in a targeted manner. If you have decided to use beneficial insects, however, you should refrain from using a pesticide, as this would harm the beneficial insects.

However, spider mites can be very stubborn, which is why we recommend using a biological pesticide if the infestation is advanced. We advise against using synthetic pesticides, especially in the home garden, as these agents usually have a high potential for damaging beneficial insects. Spider mites are also already resistant to some synthetic active ingredients. Most biological pesticides against spider mites are based on rapeseed oil. The oil ensures that the pests die on direct contact. It is therefore important to moisten the plant with the spray mixture in as many infected areas as possible. Several treatments are usually necessary for good effectiveness.

If you grow your tomatoes in the greenhouse, as a preventive measure you can make sure that the air in the greenhouse does not get too dry. Spider mites feel particularly comfortable in dry air, which is why humidifying the air can help. We also recommend reduced nitrogen fertilization and a good supply of potassium to your plants. This will make your plants less attractive to spider mites. You can easily achieve this with a special tomato fertilizer, like ours Plantura organic tomato fertilizer.

Some more tips on the subject Recognize, prevent and fight spider mites we have compiled for you in our special article.

Summary: fighting and getting rid of spider mites on tomatoes

• If possible, remove heavily infested parts of the plant
• Spray off infected plants with water every day
• Put the plastic bag over the infested plants for four days
• Targeted use of gall mosquitoes or predatory mites
• Biological pesticides based on rapeseed oil
• As a preventive measure, ensure that the air in the greenhouse is not too dry
• Reduced nitrogen fertilization and a good supply of potassium to your tomatoes

Tomato leaf miners

Tomato leaf miners (Tuta absoluta) have only been a pest in Germany for about ten years. The fully grown tomato leaf miners are gray-brown in color and have a wingspan of up to one centimeter. During the day, the adults hide, which is why they are usually difficult to find. The best way to recognize an infestation by the tomato leaf miner is through the damage caused by the larvae: When they eat, the larvae leave speckled mining ducts in leaves and sometimes also in Fruits. The caterpillars are permanently located in the leaf between the upper and lower leaf membranes.
Fight tomato leaf miners on tomatoes
The predatory bug is used in the commercial cultivation of tomatoes Macrolophus pygmaeus the most common measure. The establishment of the predatory bug is not that easy and quite time-consuming. A pesticide is not permitted against the tomato leaf miner in Germany. We therefore recommend preventive measures to prevent a renewed infestation in the following year. An effective biological measure is the nematode species before the tomatoes are planted in spring Steinernema carpocapsae to be applied with water on the planting area. We recommend this if you are planting your tomatoes in natural soil.

You should also avoid planting tomatoes in the same place for several years in a row. If you plant the tomatoes in pots, you should not use the soil again to grow tomatoes. And also the optimal supply of nutrients, for example with ours Plantura organic tomato fertilizer, makes the plants healthy and enables them to effectively produce defense substances against the tomato leaf miner and other pests.

Summary: Combating and preventing tomato leaf miners

• Predatory bug Macrolophus pygmaeus can be used, but establishment is complicated
• Nematode Steinernema carpocapsae as a preventive measure on natural soil
• No pesticides permitted
• Do not reuse potting soil when cultivating in pots, tomatoes and other nightshade plants (Solanaceae) do not plant several times in a row on the same area
• Optimal plant supply to keep plants defensive

Nematodes on tomatoes

Nematodes (Nematoda) are also called roundworms and occur as parasites in soil, water and living organisms. Depending on the species, the roundworms attack the flowers, leaves or roots of the tomato, but they can also be used as beneficial insects in biological crop protection. They enrich themselves by liquefying and absorbing the contents of entire cells. In addition, nematodes can also transmit viruses. Infestation is difficult to see. Indications can be withered phenomena despite sufficient water supply, reduced growth or black discoloration on the stem base.

Fight nematodes on tomatoes

Combating the harmful nematode species with a pesticide is not possible with tomatoes because no agent is permitted in Germany. So let's take a look at the other options:

For example, the cultivation of Tagetes, especially the species Tagetes patula, help with a nematode infestation on tomatoes. The Tagetes (Tagetes) produces a nematicide in its root cells - a poison against nematodes. Tagetes only help against the nematode genus PratylenchusIn general, however, it is wise and helpful to incorporate marigolds into the crop rotation, as they are not hosts for nematodes. Planting marigolds between the tomatoes is also an option, but it has a much smaller effect.

To combat tomato-damaging nematodes, we recommend consistent crop rotation or the use of resistant varieties such as: 'Campari', 'Dolcevita', Tropical 'Matias' and 'Piccolino' and the base ’Vigomax’.

Summary: Controlling nematodes on tomatoes

• Tagetes as a catch crop on an area with prior tomato cultivation
• Do not grow tomatoes or other nightshades (Solanaceae) in the same area for several years
• Choose resistant tomato varieties

Preventing tomato pests: How to protect your tomatoes

In general, the best preventive measure is to offer the plants the best possible conditions. Above all, this includes a needs-based supply of nutrients. We recommend that you ensure a good supply of potassium and moderate nitrogen fertilization. Suitable fertilizers, like ours Plantura organic tomato fertilizer, help you to optimally care for the tomato plants. A planting distance of around 70 centimeters in the natural soil reduces the competition for nutrients and slows down the spread of diseases or pests.

Many pests feel particularly comfortable in greenhouses. We therefore recommend regularly checking the plants for pests, especially in protected cultivation, in order to prevent mass reproduction. Some pests also like dry air, which is why you can work preventively with a slightly increased humidity.

In the garden, promoting beneficial insects is another very helpful way of preventing problems with pests. We recommend that you use plant protection that is gentle on beneficial organisms, for example with compatible household products and organic plant protection products. You can also welcome beneficial insects with breeding facilities such as an insect hotel. A meadow of flowers that is as pristine as possible offers beneficial insects a home in your garden. Our Beneficial magnet is a seed mix that makes it easy for you to create such a flower meadow.

A sensible one Crop rotation in tomatoes helps you not to leach the soil unilaterally and stops the accumulation of diseases and pests from one year of cultivation to the next. We therefore recommend that you use a different crop, such as lettuce (Lactuca sativa) or spinach (Spinacia oleracea) to plant. Plants related to tomatoes such as potatoes (Solanum tuberosum) or eggplant (Solanum melongena) you should also not grow there during this time, as these can be attacked by the same diseases as tomatoes.

A heavy pest infestation is due to a Mixed cultivation of tomatoes less likely than if you were planting a monoculture. With their essential oils, for example, parsley (Petroselinum crispum) and basil (Ocimum basilicum) Keep lice away from tomatoes. Onions (Allium cepa), Leek (Allium ampeloprasum) and garlic (Allium sativum) are also excellent neighbors for tomatoes, as they are mainly whiteflies (Aleyrodidae) to evict. Tagetes are a nice splash of color in the bed and help a little against root nematodes.

A mixed culture is not only useful with regard to pests. The socialization of different plants in a bed ensures that the soil surface is more shaded. This not only protects the soil from drying out, but also suppresses weed growth. In addition, the nutrients present in the soil are better used than if only one species is planted in the bed.

Not only pests can endanger the tomato harvest. So arise Tomato damage also for environmental and physiological reasons. We will show you how you can recognize these and prevent them.