The use of Sevin dust on vegetable gardens is controversial. This pesticide is toxic to insects and kills them within minutes of contact.
Gardeners in the United States freely use Sevin but the chemical is banned in many countries like the United Kingdom, Denmark, Australia, Germany, Sweden, Iran, and Angola.
We have done some digging and in the following article, we will discuss the safety of Sevin dust for vegetable gardens.
Sevin dust safety
Carbonyl, a powerful neurotoxin for insects, is commonly sold under the brand name Sevin. The dust form is popular for its ease of use but it is also available as a spray and in granules. Exposure to a carbonyl, whether eaten or touched by an insect, disrupts the nervous system. Unfortunately, beneficial pollinators, like honeybees, are also affected in a negative way.
This chemical has been commercially available since 1958 and is inexpensive to make. However, the safety of Sevin dust on the vegetable garden appears to be contentious worldwide with different countries adopting different policies regarding its use. The United Kingdom believes that Sevin causes cancer in humans and does not allow its sale.
The United States, however, has Sevin registered for use on vegetables and it is the third most used garden chemical there.
The list of ailments reputed to arise from its use, even where it is registered, is long. Accidental exposure results in blurred vision, blood pressure drops, nausea, diarrhea, and breathing difficulties.
Continuous inhalation of the dust causes Black Lung Disease, complications of which include heart failure, lung cancer, and respiratory failure. Pregnant women must avoid exposure as it can cause fetal abnormalities.
Using Sevin dust
Sevin kills insects when they make contact with the product or ingest it. The dust is applied by shaking it out of the container throughout the garden. Attention should be paid to the parts of the plant the insects are attacking and coat those areas. This systemic insecticide works on many pests in lawns and gardens including aphids, Japanese beetles, cutworms, squash borers, grubs, moths, beetles, cockroaches, and mosquitoes.
As soon as an infestation is apparent, apply Sevin dust to prevent a population outbreak and the need for repeat treatments. The timing of the applications should coincide with dry weather. Rain and irrigation will decrease the effectiveness of the dust as it will wash off. Let a minimum of seven days elapse between applications with a maximum of four to seven applications a year.
Personal protective equipment, like rubber gloves, dust mask, long pants, and long-sleeved shirts, should be worn when applying Sevin dust. Select a calm day for application and avoid working in the dust cloud.
Do not allow pets and children back into the treated area until all the dust has settled, at least for a day. If you inhale the product or otherwise come into contact with it, seek medical attention.
Is Sevin dust safe for vegetables?
Sevin should only be applied when there is a very clear need for its use. Even in the countries where it is legal to use, the chemical is considered toxic and should be applied with extreme caution.
Suggested wait times from spraying with Sevin to consuming the vegetables depends on the vegetable and most often ranges from three to 14 days. The pre-harvest interval, or PHI, is a statistic that indicates how soon you can harvest and consume a vegetable after applying a pesticide.
Peppers, eggplants, and other fruiting vegetables have many insect pests. The same is true for members of the brassica family, which includes broccoli, brussel sprouts, cauliflower, cabbage, Chinese cabbage, collards, kohlrabi, and mustard. Sevin can be used for the treatment of many pests on these plants. The PHI recommendation is not to harvest or eat any of these vegetables within three days of the chemical application.
Leafy vegetables require a longer time frame between Sevin application and harvest of the vegetables. Wait two weeks for celery, endive, lettuce, parsley, spinach, and other leafy vegetables. Beneficial insects and birds can be impacted by Sevin too. Sometimes, the predators of aphids and spider mites are knocked out by the chemical and then flourish in their absence.
Sevin dust on tomatoes
The PHI chart from the manufacturer of Sevin suggests that one day is a sufficient interval from application to harvest and consumption of tomatoes. So, in theory, you can dust your tomatoes one day and eat the fruit the next. We recommend that if you harvest a day after application, you soak and rinse your tomato fruit before eating to ensure any chemical residue is gone.
Use great care with Sevin to avoid undue exposure to kids, pets, and the environment. Once in place on your tomato plants, the pesticide provides protection for up to three months from dozens of insect pests. However, in rainy areas, the dust will wash off, so it may be necessary to reapply Sevin after the plants are dry. It’s good to water tomato plants at their base or uses drip irrigation to avoid washing the pesticide off.
Once you notice insect damage, choose a time with minimal wind and dry conditions to apply the pesticide. This should be one or two days after the last rain to ensure the plants are completely dry. Sprinkle the Sevin dust from the container onto the tomato plant, covering the leaves and fruit. Allow the dust to settle for the day before returning to the garden.
Sevin spray for vegetables
The GardenTech company makes a ready-to-use Sevin liquid concentrate. The active ingredient is zeta-cypermethrin, which is a new synthetic pyrethroid that kills over 500 different insect species on contact. It still is a problem for bees, beneficial insects, and fish. If swallowed or absorbed through the skin, it is toxic to people as well.
This Sevin spray is a non-systemic insecticide that can be used on vegetables in the garden. Sevin dust is systemic. The spray kills insects without soaking through the skins of the vegetables. Its’ manufacturer still recommends rinsing vegetables before consumption to remove any remaining insecticide particulates.
Ready-to-use Sevin formulas should be shaken well and sprayed on the tops and bottoms of the leaves and the stems of the plants. Concentrates can be mixed with water. The effectiveness of the pesticide lasts for up to three months and should be applied in dry, calm weather. This type of Sevin is broken down by the environment more easily than the dust.
Sevin dust vegetables safe after washing
Vegetables treated with Sevin dust should be washed thoroughly before consuming. Despite tight regulations on the type and amount of pesticide used on vegetables, it is best to remove residues with a good wash. Even organically grown vegetables should be washed to avoid bacteria or other contaminants. This process involves rinsing the vegetables under running water rather than soaking them in a sink.
It is generally agreed worldwide that conventionally grown produce is safe to eat. Conventionally grown means pesticides have likely been used on the vegetables. The presence of chemical residue, like that of Sevin, does not mean there is a health hazard. Residues are measured in parts per million or parts per billion, which are very tiny amounts.
If there is any doubt about the safety of your garden vegetables after treating with Sevin dust and subsequent washing, peeling your vegetables can remove nearly all existing residues. Onions and corn have inedible thick skins that are easy to remove. Cucumbers, eggplant, and potatoes have thin skins that are often removed even though they are edible. Tomatoes, snap peas, and peppers are usually eaten with the skins, so they should be washed carefully.
Cultural alternatives to Sevin
There are cultural measures to consider before using a non-selective pesticide like Sevin in your garden. Try less-toxic options as a first step. One action you can take is to choose cultivars best suited to your area. Buy disease-free seeds and transplants from trustworthy sources. Look for certified disease-free options.
Other cultural measures include controlling weeds, and feeding and watering plants to recommended standards. Plants that are healthy and growing well are more able to fight off insect pests. Row covers can be used to cover seedlings to prevent insects from laying eggs on them. Pests are also discouraged through the use of companion planting methods.
Crop rotation helps to keep insect pest populations under control. Planting a physically heterogenous garden, with short and tall plants, will attract beneficial insects too. It’s useful to keep a watchful eye out for insect damage in the early stages. That way it may be possible to pick off the bugs before they become a real problem.
Homemade Sevin dust
Dust type insecticidal alternatives to Sevin include diatomaceous earth and kaolin clay. Diatomaceous earth affects insects by absorbing the oils and fats from the bug’s exoskeletons.
The sharp edges of diatomaceous earth are abrasive, which assists in hastening the death of insects. The effectiveness of this product in the garden works as long as it is not moved around and stays dry.
Kaolin clay is a natural mineral with insect control properties. It creates a white powdery film on the foliage and vegetables. Insects will not scavenge because the clay will adhere to and irritate them. A light amount of Kaolin clay dust on a garden is effective in deterring many insect pests.
In addition to these two dust measures, any type of surfactant will help wash insects off plants. Even a little unscented dish soap in a spray bottle can be used. Bacillus thuringiensis, neem oil, and pyrethrum are less severe pesticides that can also be a gardener’s ally in their war against pests.
This review has offered you a lot of information to consider.
Here is an overview:
- Sevin dust is a powerful neurotoxin for insects that has effects on human health
- The dust is easy to apply and the effect lasts for several months under dry conditions
- Pre-harvest interval data is available to outline the amount of time required between the application of Sevin and the harvesting/consumption of vegetables
- A non-systemic liquid version of Sevin is available and effective and breaks down in the environment more quickly than the dust
- Washing vegetable or peeling is recommended after using Sevin dust
- Cultural and organic alternatives to Sevin do exist
The use of Sevin dust on vegetables can be a double-edged sword. Long used and effective, it has a bad reputation in some countries but is widely used in others.
In countries where it is legal to use, it may be worthwhile to try the newer liquid concentration that breaks down more quickly in the environment. Sevin’s effectiveness is high but it should be used with care.