Fight whiteflies: organic & natural

Small white flies on indoor plants and in the garden are just annoying. We reveal which home remedies help and how you can fight whiteflies naturally and biologically.

The term "white fly" is a trivial name for various whitefly from the family of Aleyrodidae. Like the aphids, they are counted among the plant lice. The two most important pests known as “whitefly” in domestic gardens are the cabbage whitefly (Aleurodes proletella) and the greenhouse whitefly (Trialeurodes vaporariorum).These two most common whiteflies share many similarities, such as a similar appearance and life cycle. But there are also some differences, which we will show you in this article using the correct species names.

White fly: Wanted poster

Not surprisingly, the whitefly is better known as the whitefly. These are small, white-powdered flies, about two millimeters in size. Due to their rapid reproduction, they are just as much feared pests as aphids. From the egg through several larval stages to the reproductive fly, it only takes a few weeks if the temperatures are favourable. This rapid development gives rise to several generations of whiteflies over the course of the vegetation period, which lay many new eggs every day.

The larvae cause the most damage. Like aphids, they extract plant sap from the host plants. The valuable proteins are filtered out of the plant sap and most of the carbohydrate-rich phloem juice is excreted again in the form of honeydew. Honeydew sticks the leaves together and provides a perfect breeding ground for sooty mold fungi. These hinder the plant's photosynthesis by growing on the honeydew-stained leaves without penetrating the plant. Furthermore, the whitefly can also be a carrier of plant viruses if it has recently suckled on a virus-infected wild plant, for example. Some of these plant viruses are very harmful to the plant, some simply reduce their beauty - and unfortunately cannot be combated.
So often the infestation with the whitefly and its nutrition at the expense of the plant is not the biggest problem. Rather, sooty mold or viral diseases can cause much greater damage. The main infestation times are late summer and autumn, since large populations are already at work at this time. In warm early summers, the infestation moves forward.

This is how you can recognize the damage caused by the whitefly

Spotting the whiteflies involves inspecting the undersides of the leaves of potential host plants. Because both adult animals and larvae sit well hidden on the underside of the leaf and the eggs are also laid there. A characteristic feature of the white-yellow eggs of the white fly is that they are deposited in a ring on the underside of the leaf. After hatching, the whitish to yellow-green-brownish larvae are mobile at first, in later larval stages they then settle like pocks. Flies about two millimeters in size as well as various larval stages and eggs can often be found on the underside of the leaf. When the plant is touched, the adult insects fly away in an arc. The small insects are encased in wax dust. Therefore, another sign of an infestation is the white dust on plant parts, potting soil and of course the small white insects. A sticky coating suggests honeydew excretions − if it turns black, sooty mold fungi have already settled.

You can recognize a whitefly infestation by the following symptoms:

• Two-millimeter white winged insects
• White-yellow eggs are laid in a ring on the underside of the leaves
• White dust on plant parts or potting soil
• Sticky coating on the leaves and possibly sooty mold fungi on them

These plants attack the white plant pests

Commonly referred to as whitefly, whitefly species prefer different host plants. In our gardens, most damage occurs to tomatoes and brassicas.

White fly on cabbage

The cabbage whitefly infests all cabbage vegetables. Cauliflower, broccoli, savoy cabbage, green and Brussels sprouts are particularly popular. The adult flies can hibernate on Brussels sprouts and then quickly build up new populations in the spring. But even removing cabbages over the winter does not guarantee that whiteflies will not appear next year. In winter, adult cabbage whiteflies also find other cruciferous plants (Brassicaceae), such as winter oilseed rape, to overwinter.

White fly on tomatoes

Tomatoes are attacked by whiteflies much more frequently in the greenhouse than outdoors. The warm, humid conditions in the greenhouse are particularly ideal for the greenhouse whitefly. They are not choosy and infest a wide range of vegetables such as tomatoes, cucumbers and zucchini.

Whitefly on indoor plants

The greenhouse whitefly in particular likes to infest indoor plants. The evenly warm temperatures and the lack of predators give these whiteflies ideal conditions for reproduction in the home. The whitefly has its sights on various indoor plants, but the poinsettia (Euphorbia pulcherrima) affected.

Fight whitefly

A heavy whitefly infestation can severely damage the laboriously planted and tended vegetables in the home garden. Both the damage caused by sucking the plant sap and the infestation of sooty mold fungi and the spread of viruses can only be reduced by combating the whitefly.

Control whiteflies biologically

Although whiteflies are an annoying plant parasite, synthetic pesticides are not necessary to combat them. Especially in the home garden and in the apartment, we always recommend choosing a biological method.

An environmentally friendly and very effective way of fighting whiteflies is neem-based preparations. The neem oil from the seeds of the neem tree contains the active ingredient azadirachtin, which is absorbed by the insects when sucking on the plant. The larvae of the whiteflies are prevented from developing by Neem preparations and the whiteflies disappear. Our Plantura Organic Pest Free Neem is based on this highly effective and purely plant-based active ingredient from the neem tree. The active ingredient is absorbed by the insects when sucking and ensures that they quickly stop sucking. The agent is simply mixed with water and the emulsion sprayed onto infested plants with a spray bottle. Precise information on the dosage and application of Organic Pest Free Neem can be found on the product packaging. With Plantura organic pest-free neem you can also successfully control other biting, leaf-mining and sucking insects, for example Fight aphids naturally. Our organic pest-free neem can be used both in the home and in the garden and is also not dangerous for bees. Please note that our organic pest-free neem must be used exactly as specified in the application recommendation in order to rule out undesirable effects.

Summary: Control whitefly biologically

• Mix organic pest-free neem with water according to the package insert
• Apply the emulsion to the affected plant with a spray bottle
• Young shoots are protected by the systemic effect and do not have to be treated afterwards
• Whiteflies are completely killed after two weeks at the latest

In addition, agents based on rapeseed oil or orange oil can be used to control whiteflies. The oil prevents the insects from getting enough oxygen and causes them to die off. Canola oil supplements also kill eggs that have come into contact with the oil. However, some soft-walled plant leaves do not tolerate these agents very well.

Home remedies for whiteflies

If you have a mild whitefly infestation, you can also use home remedies. A commonly used home remedy for plant lice is nettle broth. Since whiteflies belong to the plant lice, nettle brew can also be used against them. Here, 500 grams of fresh nettles are brewed with five liters of boiling water. The cold brew can then be sprayed onto the affected plant several times a day.

A soapy solution of 30 grams of potash soap or 200 milliliters of soft soap in one liter of water can also be applied to the affected plant several times a day. We recommend covering the soil around the infested plant with a thick cloth so that not too much soap gets into the soil.

Other control options for whiteflies

Synthetic pesticides are also available to combat whiteflies. Active ingredients such as acetamiprid not only damage whiteflies, but unfortunately also beneficial insects in your garden, which is why we recommend natural measures. Plant protection products against whiteflies can also contain vegetable pyrethrins. However, these active ingredients are also harmful to beneficial organisms. We therefore advise against using them.

Another environmentally friendly measure for a light infestation is yellow glue boards. These can be placed near infested plants and their yellow color attracts whiteflies, which stick to the panels. However, you should only use the yellow glue traps indoors or in the greenhouse because of the yellow color bees or other useful insects can also be attracted and these then also stick would. Basically serve yellow boards however, the early detection of insects rather than combating them and are only sufficient in a few cases.

Successfully combat whitefly:

• Means based on neem oil are effective and environmentally friendly, such as our Plantura Organic Pest Free Neem
• Preparations based on rapeseed oil are suitable for hard-leaved plants
• Home remedies such as nettle suds and soapy water can help with a mild infestation
• Yellow glue boards can help with a light infestation in the interior or indicate the infestation

Prevent whitefly

You can prevent an infestation by whiteflies with a few tricks: Whiteflies are attracted by the smell of some plants - for example thyme (thymus), basil (Ocimum basilicum), sage (Salvia officinalis) and tagetes (tagetes) – expelled. You can take advantage of this and place plants that have been infested before in a targeted manner next to these plants that exude their scent. You can also see flowering native wild herbs such as chervil (Anthriscus sylvestris), plant in your garden. These flowering herbs attract beneficial insects like parasitic wasps that fight whiteflies. Our Plantura beneficial insect magnet is a seed mixture with plants that promote beneficial organisms and offers you the opportunity to promote beneficial organisms in your garden in a simple way.

An optimal supply of your plants with nutrients is important both outdoors and in the living room, so that pests do not have an easy time of it. Plant-specific fertilizers will help you meet your plant's nutritional needs. We recommend that you pay attention to a good potassium and calcium supply for stable cell walls and to fertilize organic nitrogen, which is gradually released. Our Plantura organic fertilizer enable you to fertilize outdoors and indoors as required.

Especially in the living room, a bright and well-ventilated location for your plants has a preventive effect against infestation by whiteflies. This enables them to grow vigorously and increase resilience.

Summary: Preventing whitefly

• Plant strongly scented plants in the immediate vicinity
• Encourage beneficial insects in the garden
• Optimum supply of nutrients to the plants
• Indoors, light and well-ventilated location for healthy plants

You can find more natural remedies against annoying plant pests in our Shop for plant protection & insect repellent Find.