Using Sevin Dust on Green Beans

Sevin dust is a powerful herbicide that is composed of the chemical carbonyl. It is easy to use and available in granules, as a spray, and of course, as a dust. It works by disrupting the nervous system of insect pests – but unfortunately, it is indiscriminate in that it can negatively impact beneficial pollinators, too.

Sevin dust is safe to use on green beans. It works to get rid of many pests, including aphids, cutworms, moths, grubs, beetles, cutworms, and Japanese beetles. Just make sure you wash and rinse your beans thoroughly before you freeze or eat them, regardless of when you use Sevin dust during the growing process.

As mentioned earlier, Sevin dust is labeled as safe for use on beans. However, there are a few things you will want to be aware of before you decide to use it on your plants. Here’s what you need to know…

What is Sevin Dust?

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Sevin dust is a chemical that can be used in the garden to control a wide variety of pests. It contains the active ingredient carbaryl.

It kills insects on contact, affecting them either when they make bodily contact with the chemical or when they ingest it.

It is applied by shaking it via a container throughout the garden, with particular attention paid to the plant parts that the insects are actively feeding upon.

Sevin dust can get rid of the following pests:

It should be applied as soon as you notice an infestation and repeatedly until the infestation is gone. You must apply this chemical when the weather is dry, as rain will reduce the effectiveness of the dust. You can apply it up to seven times per year.

Sevin dust is meant to be applied after you have planted to protect your garden edibles from insect damage. You do have to follow a pre-harvest interval chart, which varies depending on the type of plant you are growing.

While plants like brassicas can be harvested pretty soon after applying Sevin dust, things like apples, tomatoes, peppers, and cherries need a longer interval. Leafy vegetables like kale, collards, lettuce, arugula, spinach, and cabbage also need a longer wait time (referred to as PHI) before they’re safe to eat.

Check the product labels on the specific Sevin products you use to find out when it’s safe to eat the harvest from your vegetable garden.

What are the Risks of Sevin Dust?

Sevin dust is registered with the U.S. Environmental Protection Agency for use on vegetables. However, it is toxic and you do need to be careful when you apply it. The manufacturer suggests waiting three to 14 days before eating beans that were sprayed with Sevin dust, since carbaryl can be moderately toxic.

It can produce adverse effects regardless of whether you inhale it, ingest it, or via skin contact. This is why many countries, like the United Kingdom, no longer allow its sale.

Although you’ll be fine when you use Sevin dust as long as you use it correctly, using too much or harvesting too soon after you have applied it can lead to severe symptoms. You might suffer from black lung disease (especially if inhalation is involved), nausea, lowered blood pressure, blurred vision, diarrhea, breathing difficulties, and more.

Not only that, but pregnant women should avoid using it as it can cause fetal abnormalities.

Despite the risks, it can still be a good solution to get rid of green bean pests, especially when nothing else seems to work. If you must use it, wear personal protective equipment like rubber gloves and a dust mask so you can reduce your contact with the chemicals. Apply only a calm, rain-free day so you don’t have to work in a dust cloud.

Remember that beneficial insects, like bees and butterflies, will also be affected by Sevin dust. It can also affect birds and animals that might feed upon those insects.

Make sure all kids and pets aren’t allowed into the treated area for at least 24 hours. Only apply Sevin dust if you absolutely need to. It is toxic and needs to be treated with extreme caution.

You can remove most traces of this pesticide by thoroughly washing and rinsing your plants. The chemical residues will only exist in very small numbers (parts per million) after that.

Although this technique won’t work as well for plants like peas and green beans, peeling your vegetables can remove almost all lingering residues before you eat them, too. Therefore, if you use Sevin dust on cucumbers, potatoes, or something else like that, you can safely eat them after harvest.

What Pests Attack Green Beans?

There are a few pests that are more common on green beans than others.

These include western spotted cucumber beetles, Mexican beetles, spider mites, thrips, and aphids.

If you’re trying to get rid of pests and prevent their damages, your first step should be to identify the pest you’re working with. Applying Sevin dust won’t be very effective if you don’t even know what you’re trying to kill!

Cucumber beetles and Mexican beetles are closely related to lady beetles, but unlike lady beetles, they are not helpful in the garden. They feed upon plant tissue. Cucumber beetles are bright green with black spots, while Mexican beetles are copper-colored with black spots.

Aphids are small, feeding specifically on beans. They can be black or green and feed by sucking on plant juices.

Not only can they damage plants through this sucking mechanism alone, but they can also spread a variety of viral and bacterial diseases. Plus, they leave behind honeydew as they feed, which is a sticky substance that can attract hordes of ants.

Thrips are shaped like spindles and can be brown, black, amber, or yellow. They leave tiny black excrement behind as they feed and are most common in hot, dry weather.

Finally, spider mites are hard to spot, but may leave behind silk webbing that gives you an indication that these pests are to blame.

Other Pest Control Options for Green Beans

Fortunately, Sevin dust isn’t the only way you can control pests on green beans – although it’s often used as a last (and necessary) resort for many gardeners. Here are some other things you can try before resorting to chemicals.

Keep a Weed-Free Garden

Try to reduce weeds as much as possible in your garden. This can help prevent pests from laying their eggs and overwintering in the garden – plus, it reduces their hiding spots.

When plants aren’t competing with nearby weeds, they’ll grow stronger, and be able to resist the threat of pests a bit easier, too.

Use Row Covers

Row covers are incredibly beneficial when it comes to preventing insects from laying their eggs on plants. Cover up seedlings when they are the most fragile, then remove the row covers when it’s time for the plants to be pollinated.

Try Companion Planting

Companion planting is a classic technique that can work wonders in preventing pests. Certain insects are repelled by certain plants.

For example, you might try growing catnip near beans to repel flea beetles. Marigolds can deter Mexican bean beetles as well as many other insect pests (along with microscopic worms). Nasturtium and rosemary help deter bean beetles, too, as do potatoes.

Plant Resistant Varieties

If you have a known pest problem in the garden, it might be a good idea for you to plant pest-resistant varieties. Even those that are listed as early-maturing may be able to better withstand pressure from pests.

Rotate Your Crops

Don’t plant your beans in the same spot each year. Some insects lay their eggs in the soil – meaning as soon as those eggs hatch into larvae and develop into adults the following spring, they’ll have plants to feed upon immediately. You can avoid this by simply moving your crop to a new location in the garden each year.

Try Diatomaceous Earth or Kaolin Clay

If the idea of dusting your garden to remove pest pressure appeals to you, consider using diatomaceous earth or kaolin clay instead. Both of these are natural solutions that work well, especially when dry.

Diatomaceous earth is a product that consists of the ground-up exoskeletons of microorganisms. It has super sharp edges that won’t affect you, but are abrasive to insects. It cuts up their exoskeletons and dehydrates them, killing them quickly. Like Sevin dust, it needs to be reapplied after a rain.

Kaolin clay is another natural mineral with insect control purposes. It produces a white powdery film that irritates most insect pests.

Try Hand Picking

Some pests are easy enough to control by simply plucking them off the plants, especially when the infestation is minor. Just pull pests off the plants and drop them in buckets of soapy water!

Use a Less Harmful Insecticide

Even something as simple as a mild surfactant (like dish soap) can keep most green bean pests at bay. Using unscented dish soap in a spray bottle or something like pyrethrum, neem oil, or Bacillus thuringiensis (a soil-borne organism) can help kill pests in a more eco-friendly way. A natural insecticidal soap can be helpful, too.

Ensure Conditions are Up to Snuff

Take a good, hard look at your plants and their growing environment. Are you giving them everything they need to be healthy?

Most of the time, plants can withstand pressure from pests if they are grown in fertile, well-draining soil and are given the water, fertilizers, and sunlight they need to be healthy. See if there’s anything you can do to improve the growing conditions.

Water, in particular, is something to keep an eye on. Plants are more likely to suffer from an intense insect attack when they are drought-stressed. Plus, if you water diligently, you can often knock insect pests off the plants with a blast from the hose.

Clean the Garden Up

At the end of the growing season, don’t just leave your bean plants in the garden to rot. Although this works wonders when it comes to fertilizing the soil, it allows insect pests and their eggs to overwinter.

Green Bean Pests – My Personal Dilemma

Having a little problem here as you’ll see in the picture.

Notice anything in particular? Yeah, HOLES, everywhere! My poor poor green beans, well, what’s left of them after the chickens had a field day scratching in this particular bed, have been pretty much obliterated by some unidentified munching creature. (The little tiny flying bugs all over the backs of the leaves, perhaps?)

green bean plants eaten by Mexican beetles
green bean plants eaten by Mexican beetles

I haven’t really been able to identify what kind of pest is causing my green beans to suffer – and while I don’t want to resort to Sevin dust, I may have to.

I’ve tried spraying the plants with organic insecticides like the ones I mentioned above, but the problem with that has been that it can’t rain for 24 hours after applying the spray… and it has been raining every other day for several weeks now! So, the sprays have done no good.

My mother-in-law suggested that I add some lemon scented dish soap to some water and spray both sides of the plant’s leaves with that… but like I said, it hasn’t stayed dry long enough for it to help. I’m about to dig all of these up and replant the bed.

I don’t love the idea of using Sevin dust on my plants, but it might be the only remaining option in order to have my poor green beans. The good news is that, as long as you wash the produce well, it will be safe enough to eat.

updated 12/13/2021 by Rebekah Pierce

22 thoughts on “Using Sevin Dust on Green Beans”

  1. Always read the fine print……..I recently went to a local home and garden store to purchase something to “take care of” whatever has been eating my raspberry leaves. A man who has worked there for quite some time, commented “well, you would want something Earth friendly and organic”. Absolutely I said. He handed me a very friendly looking bottle of soap spray. After spraying the plant, wait so many hours, and you can eat the fruit with no problem…..well, he also said, “but you can’t “”can”” anything you spray with this…. “what???????” It’s organically labeled, you can eat it after so many hours, but you can’t “can” what you spray?????? I am bringing this up, because many of us have purchased items in bulk to “can” from local garden stands, and we have grown items, and used “insecticide soaps” on them. It got me thinking of what we have ingested, and changed the character of by the heat process of canning. If Earth friendly can harm us, what are the local stands and grocery store suppliers using? Food for thought. Keep knocking those bugs off if you can find them……smooosh them……stomp them……drown them. Be merciless, because obviously anthing we can buy to kill them, will probably kill us, sooner or later. P.S. …and always, always, remember to rotate your crops every year!

    Reply
    • I completely agree with you and this whole “Organic” Craze. People really need to pay attention to what Organic means. WAY TO HIGH mineral amounts put on the plants that goes right into the food we eat. Plus a bunch of other bad practices that go into the ground and right into the person that eats the “whatever it is product”. Just stick to home remedies and picking. It will be safer for you. Happy Planting, Growing and Eatting.
      Maria Sergent
      EM’s Garden Market

      Reply
  2. Wow, sounds like you got lots of advice here. I always seem to email and forget that it’s not the same as comments.

    In summary of what you’ve already read from me and if it might possibly help others.

    If you look under the leaves and there are small yellow orange larvae or small yellow/orange beetles with black spots, then your problem is bean beetles. These guys are BIG eaters and will ruin your beans as well as foliage.

    I have in the past used NEEM oil spray on them. You can add to that some hot pepper sauce or cayenne powder (probably ought to strain it if you do so it doesn’t clog your sprayer). A little goes a long way and is essential to any gardener. Spray the tops and bottoms of the leaves and repeat a few times especially after a heavy rain, though because this is an oil it will stick to the leaves and won’t need to be repeated quite as often as a powder. Most powders are toxic anyway and not something I like to put into the garden.

    After I wrote to you I found a couple sites that had some interesting information on bug sprays that use household items and I know you like that…

    http://www.discoverneem.com/

    and

    Hope these help ya…

    Unless the bean pods are already infested, I’d try the oil before pulling them up and replanting, but then you’re in a place with a longer growing season, so it may work for you. We wouldn’t have enough growing season for new plants to grow at this point.

    God Bless,
    Mrs. D

    Reply
  3. We had the same problem last year and we’re having it again this year. They’re definitely beetles! We got a beetle trap at Home Depot that wasn’t very expensive. It’s a bag with a scent pad at the top that you hang downwind of the plants. The beetles are attracted to the scent and wind up dead in the bag….just tie up the bag when it gets full and throw it in the garbage. I think we used two bags the whole summer. As soon as we hung the trap, the beetle problem instantly got better!

    Reply
  4. about the sevin dust, you can also put some in a knee high stocking and shake it around where you want it and it will come out in a fine dusting all over, it saves alot too. I just never had luck with the organic stuff, except for fertilizers.

    Reply
  5. We had the same problem. If the “flying” bugs are tiny black ones than they probably are the problem and they’re called flea beetles. If you spray both sides of the leaves with a hot pepper spray (~1 Tbspn tabasco sauce, ~ 1 Tbspn dish soap and 32 ounces of water in a spray bottle) you should be able to get rid of them. It’s okay if it’s going to rain, as you want to reapply this every 2-3 days anyway. This worked for us just a couple of weeks ago.

    Reply
  6. Ooooh, I agree. I think you have flea beetles and if left alone, they will eat every bit of your leaves. We lost all of our eggplant last year.

    Also, try to get on the mailing list of Garden’s Alive catalog. http://www.gardensalive.com/default.asp?sid=140271&eid=&bhcd2=1275567625

    They will often have $25 off coupons on their catalog with NO MINIMUM ORDER. I just “purchased” Liquid Rotenone/Pyrethrin Spray which is an organic insectide.

    Good luck!

    Shannon

    Reply
  7. I agree with Jen about the chili powder and cinnamon. I’ve heard it said before and forgot about it. I’ll probably be doing that to my brussels sprouts tomorrow. The yellow is probably from too much water. But if the pic you put up with your post is what your plants look like, then you should be fine. You should still get beans. I planted beans as well and they arent producing anything yet. It’s been at least 6 weeks. Also, if you’ve gotten so much rain, it might be causing your beans not to grow as well as some of the other plants. Tomatoes love water and sun. Give them plenty of both and they are good to go. Im not so sure that beans have the same philosophy. I would keep them anyway. Maybe put a tarp loosly over them if you are getting more rain just to keep the water from drowning the poor plants. That’s my advice, I hope this helps!

    Reply
  8. Just sprinkle some sevin dust on them. Yes, I know it’s not organic, but neither is most of the stuff in the store. Better something than nothing. It will knock most of the bugs out. some years are worse than others. There will be new growth too, and it won’t have the sevin on it. It will kill the bugs and has been around awhile. I just take an old can and put a tons of holes in the bottom with a hammer and a nail. I put the sevin dust in there and tap the can to dust the plants. You can also do the dog a little as well for fleas. Sure, frontline works great but who has $ for that? That way the dog doesn’t scratch bald spots which turn into something else. I do like organic stuff a lot, but some of the treatments are too expensive.

    Reply
  9. The yellow is probably from all the rain…too much water.

    In my garden I sprinkle chili powder and cinnamon. I buy the big containers of it in the seasoning isle of Costco. It cleared an entire ant hill in my garden last year and kept squash bugs at bay and snails away. It was really effect so I’d give it a try. It might cling to the leaves longer than the soap spray (which I also use too) does in the rain.

    Reply
  10. Are they actually killing the plants?? We had this problem one year and left it go, they never killed the plants and we still got beans. Good luck!!

    Reply
    • Tabatha,

      Most of the plants are yellow. I think they can be counted as goners! None are blooming or anything. Maybe I’ll let them go and see what happens. Some tomato plants that I totally expected to die are actually doing better than all of the rest now, so maybe I’ll be pleasantly surprised.

      Reply

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