Pests on houseplants are annoying, but unfortunately not uncommon. Suddenly the leaves become sticky, show light spots, or the plant appears weakened overall. The first impulse is often to immediately resort to strong, chemical pesticides. But that's not always necessary. There are also effective and gentler alternatives. For natural pest control in houseplants. So-called N Beneficial insects and various home remedies can also help to effectively control pests without unnecessarily burdening plants, people or the environment.
What is meant by natural pest control?
Natural pest control refers to methods that combat or keep pests in check without the use of chemical-synthetic pesticides. Instead of resorting to harsh chemicals, natural mechanisms are used to restore the balance between plants and their environment. Besides the mechanical removal of pests, for example by wiping the leaves, rinsing the plants in the shower or selectively removing heavily infested plant parts, there are two main measures for natural pest control in houseplants:
- Beneficial insects: Natural enemies of pests that eat them or control their reproduction.
- Home remedies: Various plant-friendly remedies that can combat or repel pests.
Beneficial insects against pests
Beneficial insects are living animals that act as natural enemies of pests. They eat the pests or inhibit their reproduction, thus naturally reducing infestations significantly. Beneficial insects can be used both to combat an existing infestation and preventively to prevent recurrence.
Frequently used beneficial insects
Which beneficial insects are suitable for pest control always depends on the type of pest. and the extent of the infestation. Therefore, it is important to determine the infestation as accurately as possible. This is the only way to use beneficial insects in a targeted and successful manner. Frequently used beneficial insects include, for example:
- SF nematodes: Control pests living in the substrate, such as fungus gnat larvae.
- Predatory mites: Effective against spider mites and thrips
- Ladybug larvae: Very effective against aphids
- Lacewing larvae: They primarily feed on aphids, thrips, and mealybugs on leaves and shoots.
- Parasitic wasps: Effective against whiteflies , aphids, and mealybugs
The correct use of beneficial organisms
For beneficial insects to effectively reduce pests, proper application is crucial. Beneficial insects can easily be ordered online. Since they are living organisms, they should be used immediately upon receipt.
The exact application method depends on the specific beneficial organism. Nematodes are mixed with water and then introduced into the soil via the watering can. They move around in the soil, combat the pests, and then die off on their own once no more food is available. Predatory mites, lacewing larvae, or ladybug larvae are either sprinkled directly onto the plant, placed on leaves, or attached using special carrier materials (e.g., cardboard strips or bags). From there, they actively search for pests. Depending on the severity of the infestation, several applications may be necessary.
When using beneficial insects, it's also important to adjust the ambient temperature and humidity to their specific needs. They can only become active and effectively control pests under suitable conditions. During this time, chemical pesticides should not be used, as these can harm or kill not only pests but also the beneficial insects. Furthermore, it's advisable not to shower the plants in the days following their release, so that the beneficial insects can establish themselves undisturbed on the plant or in the substrate and exert their beneficial effects.
And don't worry: Using beneficial insects doesn't simply replace pests with other animals. The beneficial insects don't reproduce uncontrollably and don't stay in the home permanently. Once the pests are gone, the beneficial insects lose their food source and either die off or disappear on their own.
Home remedies for pests
Another way to naturally control pests in houseplants is to use home remedies. Many of these have proven effective over time and are easy to make yourself. Most are spray mixtures that work against various pests by attacking their protective layer, hindering their respiration, or repelling them from the plant. These mixtures should be sprayed on the infested plant at regular intervals. It is important to treat the plant from all sides, especially the undersides of the leaves, as pests are particularly likely to be found there.
Soapy water
A mild soap solution is well suited against aphids, mealybugs and thrips.
Mix about 1 liter of water with a small dash of soft soap or bar soap, preferably without fragrances. The soap dissolves the protective wax layer of the pests, causing them to dry out and die. Spray the soap mixture onto the infested area approximately every three to five days. Plant until no more signs of pest infestation are visible.
Oil blends
Oil-based mixtures work by blocking the pests' breathing pores. Mix approximately... 1 liter of water with 1-2 teaspoons of oil. Optionally, you can add a drop of dish soap or mild soap to help the oil and water mix better. Suitable oils include, for example, commercially available rapeseed oil or olive oil. Neem oil is also a proven natural pest control agent. It is available in garden centers, hardware stores, or online and is usually sold as a concentrate.
The oil mixture should be sprayed evenly onto the plant. If applied correctly, a permanent, airtight film will not form on the plant. This is because the oil is highly diluted. Once dissolved, it spreads finely and breaks down over time. It is important to use the mixture sparingly and not in direct sunlight to avoid leaf damage.
Additional measures
In addition to home remedies and beneficial insects against pests, various supportive measures can be used:
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Yellow sticky traps: The yellow color attracts the insects, causing them to stick to the sticky surface.
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Blue sticky traps: Thrips in particular are attracted by the blue color and stick to the surface of the blue sticky traps.
- Matches: These are inserted into the ground with the head pointing downwards, allowing the sulfur they contain to enter the substrate when watering, where it can inhibit the development of larvae.
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Cinnamon: Can be sprinkled thinly onto the substrate surface and has a slightly fungicidal and repellent effect.
- Substrate covering: For example with sand, quartz sand or clay granules, makes it difficult for pests such as fungus gnats to lay their eggs.
Furthermore, it is important to check plants regularly, both in case of an acute infestation and as a preventative measure. The earlier pests are detected, the easier and gentler they can be controlled.
Natural pest control: step by step
- Identifying pests: Examine the leaves, shoots, and substrate carefully and identify the type of pests. Common examples include fungus gnats, thrips, or aphids.
- Choose appropriate measures: Depending on the type of pests, choose suitable measures, for example beneficial insects, home remedies or a combination of several methods.
- Use natural pest control methods: Apply home remedies thoroughly to the houseplant, correctly release beneficial insects, or set up signs.
- Repeat regularly: Check your plant every few days and repeat the applications as needed.
Naturally prevent pests
While pest infestations cannot always be completely avoided, the risk can be significantly reduced with some preventative measures. As a general rule: Healthy plants are less susceptible to pests.
- A suitable location: In brighter locations, the risk of pests can often be significantly reduced.
- Watering according to need: Prevents stress and waterlogging, which can encourage pests.
- Appropriate humidity: Many pests multiply particularly well in dry air from heating systems; regular spraying can have a preventative effect.
- Plant strengthening: Balanced fertilization and natural plant strengtheners make plants more robust.
Regular monitoring, proper care, and targeted natural methods allow you to detect pests early and effectively control them. Beneficial insects, home remedies, and other supportive methods offer a gentle alternative to chemical pesticides. It's important to apply these measures consistently and repeat them as needed. This will keep your houseplants healthy and resilient in the long run.
