Fire Ants in the Garden

Ants can be treated with spinosad in vegetable gardens. Photo by Molly Jameson.
Ants can be treated with spinosad in vegetable gardens. Photo by Molly Jameson.

There’s nothing worse than sinking your fingers into your garden soil to dig up a potato, plant a seedling, or pull up a radish, and be met with a sharp, painful sting, and little red critters rocketing up your arms. If you are a gardener in the panhandle, my bet is that you know exactly to what I refer: fire ants!

Fire ants are certainly not native to our area. These guys are an invasive species from South America that are very resilient, and many are territorial, with the potential to drive out any native ant populations. Fire ants arrived in the 1930s, and can now be found throughout most of the southeastern United States.

So when you end up with fire ant mounds engulfing your carrot patch, what can be done? Since fire ants in your garden mean fire ants in your food, the least toxic control methods are of high importance and conventional broadcast bait treatments and mound treatments should be avoided. Even in your lawn, be careful when using strong insecticidal bait treatments, as these can harm the native ant populations that help control the spread of fire ants. This can then lead to a strong resurgence of fire ant populations that can outcompete the native ants.

Although completely controlling fire ants in an area is not possible, there are sustainable management techniques that can help. Some fire ant colonies have a single queen while others have multiple queens. Either way, in order to eliminate a fire ant colony, all queens in the colony must be killed. Fire ants are omnivorous, in that they eat plants, insects, sugars, and oils. The catch is that they are only able to ingest liquids, so solid food must be brought into the colony, where larvae regurgitate digestive enzymes onto the food, breaking it down into liquids. Therefore, any method of control by ingestion will need to be in liquid form, or the ants must be able to bring the material into the colony, without first being exterminated.

Fire ants can become a problem around and in raised vegetable gardens. Photo by Molly Jameson.
Fire ants can become a problem around and in raised vegetable gardens. Photo by Molly Jameson.

There are some commercially available products that contain boric acid or diatomaceous earth. These products may reduce populations, but eliminating whole colonies with these products can be a challenge.

The use of a nervous system toxin called spinosad is effective on fire ant populations and is considered safe to use in vegetable gardens. This toxin comes from a bacterial fermentation process, and is therefore considered organic. But be aware, even though there are organic products with ingredients derived from botanical sources such as rotenone and nicotine sulfate, they should not be used in vegetable gardens. When using chemical methods of control, always follow the directions on the label carefully.

One physical method of control is the use of hot water. Three gallons of scalding water, which is between 190 to 212ºF, has been used on colonies with a success rate of 20 to 60 percent, when applied in several treatments. You will want to slowly pour the water on the colony, being extra careful not to get burned, and avoid injuring any surrounding plants. If you are like I am, and you often leave your garden hose in the hot sun, you can spray the ant colonies with the hot water, as you wait for the water to cool off enough to water the garden. Hot water control takes persistence, but you can eventually drive the ants out.

Another method of physical control is excavation. This requires digging up the mound, putting it in a bucket, and taking it to another location. Apply talcum or baby powder to your shovel handle and bucket to help prevent the ants from escaping and crawling up to sting you.

One reason fire ants are so rampant in the United States is that they have little competition or natural enemies. Scientists have released multiple species of phorid flies, natural parasites of fire ants in South America, and a few species have become established. Scientists at UF/IFAS are currently researching additional fire ant biological control methods, such as the use of a fungi, which has shown promise.

Remember, not all ants in the garden are bad guys! Many species act as roto-tillers, aerating and redistributing nutrients in the soil. They also play a role as decomposers as they assist in turning dead insects into soil nutrients. Ants can disturb garden pests by attacking them or interrupting their feeding, mating, and egg laying processes. Additionally, ants are a food source for wildlife, such as other insects, frogs, lizards, birds, spiders, and even some mammals.



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Posted: August 12, 2016

Category: Horticulture
Tags: Best Management Practices, Boric Acid, Diatomaceous Earth, Fire Ants, General Gardening, Insects, Integrated Pest Management, Invasive Species, Panhandle Gardening, Phorid Fly, Spinosad, Vegetable Gardening


Molly Jameson

September 21, 2021

Hi Sara, Thank you for your comment! Edible ginger, Zingiber officinale, is not considered invasive and can be planted in the soil or in a pot. Here is more information, including additional links about ginger, how to grow it, and how to harvest the roots: Thank you and please let us know if you have any additional questions! Sincerely, -UF/IFAS Leon County Extension

September 20, 2021

Is edible ginger invasive or does it have a lot of spread (like Boston? ferns)? The ginger sprouted in a pot from buying a fresh organic root at the grocery store. Should I plant the ginger in my yard or keep it in a pot?

bill keiser
October 7, 2020

It may be an urban legend, but I've heard that they irradiate or treat some ginger to prevent it from growing. I always look for fresh growth nubs on ginger if I'm looking for some for planting.

Molly Jameson
August 22, 2016

Hi Ann, Sorry for the confusion. What I meant to say is that while spinosad is safe in vegetable gardens, not all organic materials are safe. Rotenone and nicotine sulfate are examples of organic materials that are not safe in vegetable gardens. Does that help? -Molly Jameson

August 20, 2016

Must be in the same family as the cypress vine - it stinks too.

Ann Robinson
August 19, 2016

In paragraph six it states that spinosad is safe for use in vegetable gardens. And then in the same paragraph say it should not be used in a vegetable garden. I'm confused. Is it okay? I've tried everything. Digging it up. Boiling water. Cinnamon. Thanks, Ann

August 12, 2016

Great Article! Thank you. Dmytro

Sheryl Butler
August 3, 2016

This is the best organic way of dealing with waste. I started researching compost opportunities while ago. This is the future if we want to keep the planet's environment and resources, of course. I didn't know much about vermicomposting, only about the standard composting methods. I know most people are used to hire a company for their waste removal needs but it is good if they consider at least to try your composting method. Thank you, Sheryl

Shannon Brady
July 7, 2016

I believe that proper and regular garden waste clearance could significantly reduce the risk of your plants getting affected by fungus and bacteria. It doesn't require much effort and if you don't have the time to do this by yourself you could always hire professional rubbish removal service.

Thomas Duke
May 25, 2016

couple of comments.....(1) As an organic farmer, mushroom compost seemed a no-brainer addition to my yearly mulch pile. However, I stopped using it a couple of years ago because of an article discussing the chemicals the mushroom folks use to reduce certain diseases peculiar to mushroom. (2) I also used straw bales to boarder three sides of my yearly mulch/compost pile and then at the end of the year incorporated the rotted straw into the compost as a "plant-based manure." However, a couple of years ago I came to understand that since straw is generally not consumed when used as a bedding material, straw farmers liberally sprays their fields with herbicides to improve the straw's "purity" from weeds Again, concerned with residual chemicals I discontinued using straw. Results from (1) & (2) = my raised-bed garden with 100% organic growing medium (no dirt) has yielded healthier plants and better crop yield. Took two years, with each year showing improvement. CONCLUSION: carefully "vet" the origins/history of the ingredients that go into your compost so you can more closely realize that garden of your dreams!

Shari Farrell
April 27, 2016

I've been growing container veggies on my deck for years. Some don't do so well and others are astounding! Tomatoes never did well for me in-ground, but large pots on the deck are perfect. Green snap beans, banana peppers and salad greens too. what few pests found are easily disposed of and soil borne troubles are nil. I will never go back to any other system.

Mary Derrick
April 26, 2016

The best time to plant potatoes here is in January/February. Also, russet potatoes are more commonly grown in more northern climes and generally not grown in Florida. See our publication on potatoes: But you can give it a try and see what happens!

April 25, 2016

Nice piece! Proud of the work of this great organization, a model for all of Florida and the country.

Matthew Orwat
April 21, 2016 This should explain the situation well. Thanks!

Stephanie Dickens
April 16, 2016

why is cypress mulch not recommended for use as mulch?

Lisa madine
April 11, 2016

My husband wants to plant a MICROWAVE Able potato. It is all ready wrapped in Plastic. It has roots growing out. We got it at Publix. It is called MICRO TATER Russet. Is it worth doing it. ?

(Rosalie) Lia
October 9, 2015

Wonderful article! Thank you! Makes me feel better about wanting to eat peanuts in ways besides the traditional Southern way which has too much salt.

September 5, 2015

I live in the fountain area, and I know I will not have the lush green grass I had in Nebraska, I have problems in my yard I do not know what to do about. Yes I have lots of turkey oaks with white around them that seems to kill the tree after time. But my main concern is I will have a nice green patch of grass, but then the edges die. Sometimes a big circle will be there with just weeds growing in it. I also have a vine that goes underbeath the soil and kills plants I can get to grown. I also have a tree in my yard that almost has leaves like a mimosa but is bright orange in the fall. Can you heip. I do not know when to go to get answers for my questions

August 28, 2015

Thank you so much for focusing on this important topic! Since moving to FL not as connected to local sources as was in NM. But I will continue to seek out local vendors, growers, farmers. I always grow things myself. Lia

June 23, 2015

Food waste is a worldwide problem, but in the US it seems it is the most major issue, excluding hazardous waste... Recently many supermarkets began a program in which they use their waste to convert it into power and use that power. As a professional dealing with almost any kind of waste, household rubbish and house clearances in London, I can really say that now is the time to make innovations and start the change - to recycle more and to produce less waste.

Cody English
February 5, 2015

Great article!

Donna Legare
January 23, 2015

Excellent article Taylor - very important. Donna

Taylor Vandiver
August 12, 2014

Donna, Thank you for the information! I will definitely add it to my list. Taylor

Donna Legare
August 5, 2014

Hi Taylor You might want to add the native hoptree (Ptelea trifoliata) and the herb rue to your list for larval plants for the giant swallowtail. Rue fits nicely in the butterfly garden and also is used by black swallowtails. Hoptree can be used outside of the garden since it makes a small tree or large shrub, doing well in a lightly shaded mixed border. Enjoyed the article. Donna Native Nurseries

Matthew Orwat
July 3, 2014

Sounds like you have a very nice wildflower garden!

Whitney Gray
July 3, 2014

Thanks, Taylor! Great info!

Lois Jones
July 3, 2014

About 15 years ago, I attended a slide-illustrated program at a Garden Club meeting. The Florida DOT's District 1 staff person for road-side wildflowers was the presentor. The Wildseed Co. of Fredericksburg, TX was recommended as source for our home landscapes. I have been planting this company's Southeastern US mix..and cosmos specialty seeds...ever since. I love to give small bouquets. I love to look at my beds in front and read of my home. In addition,my photo of coreopsis in a roadside ditch won "First Place" in photo contest! Lois Jones / Marianna since 2000; previously-Chipley

Faye Blanton
May 1, 2014

Great information! Thank you.

May 1, 2014

Hello Taylor: Thanks for the diagnosis flow charts! I have a fruit and vegetable garden at home in addition to our landscaping, and what would be helpful is a couple of definitions, and some instructions what to do once we've diagnosed the problem. Hopefully at some point someone wrote an article about how best to do that, and perhaps you could add a link. With regard to definitions, what are mobile vs. immobile nutrients? I would think "necrotic" means something similar to yellowed or scorched, but since you used the latter terms in other places in the charts, does it mean something different? What does "chlorotic" mean? Thanks for any additional information you can provide. -- Sharon McAuliffe

Kenneth Smith
February 26, 2014

Thanks for the info, now are there sources for any of mentioned plants? I live in Eastpoint-Apalachicola, FL. I did have my sandy soil tested and it is very high-very sandy!

Donna Legare
January 22, 2014

nice article, Taylor - I'm looking forward to planting our potatoes soon.

November 6, 2013

Worm composting like any other job, does require a lot of skills and patience...

November 5, 2013

Thanks for sharing a great article on vermicomposting

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